Nasiens

is a mysterious boy Percival meets at Echo Gorge, later appointed as a Holy Knight of Liones and member of the Percival Platoon.

Appearance
Nasiens is a young boy with short light brown hair and yellow eyes.

He wears a black full body suit under a white coat and a white hat. Before leaving Liones, Nasiens receives a new outfit composed of a a green suit under a white jacket with pockets for test tubes, a wider hat, and shoes with long stockings.

Personality
Nasiens seems to be a calm and serene boy, who can also be scary at times, and rarely makes his true feelings known. Although with Percival, Donny and Sin, he has managed to have enough trust in all of them to show them his emotions without hiding anything. However, Nasiens still keeps some secrets, as when Anghalhad perceived that he was hiding something.

Nasiens has a great interest in plants, wanting to be a herbalist like his adoptive grandfather Ordo was. He gets very excited when making new discoveries, liking to experiment with everything around him.

Nasiens can be very sentimental, but being isolated for so many years, he does not know how to show it; an example of this would be when he could not find the words to tell Percival that he considered him his first friend, and ended up saying "guinea pig".

History
Nasiens was abandoned as a baby in Echo Gorge and was found and adopted by Ordo. Nasiens grew up studying to be an apothecary like his grandfather, Ordo, until one day Ordo disappeared and soon after, a strange disease began to eat the life force of the plants and animals of Echo Gorge.

Nasiens started conducting experiments to create a cure for Echo Gorge, and as a side effect of some of his failed drugs, the animals and plants became monstrous and violent. This led to the local fairies to mistakenly believe that Nasiens was trying to destroy Echo Gorge.

Echo Gorge arc
In his lair, Nasiens talks to a strange fairy he is holding hostage. The fairy says that he just got lost and ended up in the Echo Gorge, to which Nasiens decides to turn him into his guinea pig. There, Percival breaks into his lair and manages to free the fairy. However, Nasiens sleeps him with belladona leaves with the intention of turning him into his guinea pig instead.

When Percival wakes up tied up and almost naked, Nasiens is surprised as the belladonna should have kept him asleep for ten hours. After mentioning the magical nature of Percival's helmet and cape, Nasiens injects him with a strange drug that makes his hair grow rapidly, to which Nasiens concludes that he could use it to accelerate the growth of plants and animals. Percival claims what he does to him and what he did to the fairy, but Nasiens explains that the fairy was the one who invaded his home and attacked him first. Nasiens says that the speed with which he responds to his treatments, Percival is the best of all guinea pigs. Percival marks the way to talk about him and how blood falls from his mouth, which Nasiens explains is a habit of biting his lip when he is excited.

While preparing a drug, Percival asks Nasiens why he is doing all this, to which Nasiens refuses to reply. There, Percival manages to free himself and recover the helmet from him, which surprises Nasiens and leads him to take up his weapons and infuse them with magic to fight Percival. Percival tells him that he is willing to help him if he needs it, but Nasiens says that all he needs are guinea pigs to finish the drug on him. When the helmet flies off the staff head due to his hair, it hits Nasiens, causing him to fall onto his workbench and Percival to catch the substance he was developing. Nasiens demands that he return it, but Percival drinks it since Nasiens wanted to test it on someone anyway.

Despite suffering at first, Percival ends up energized after drinking the substance. Nasiens asks him why he drank something so dangerous, to which Percival tells him that it was to help him since he created that substance to save Echo Gorge. Seeing his fruitful work, Nasiens drinks what is left of his pot. When the gorge fairies attack Nasiens believing him responsible for the disaster in his home, Percival defends him by revealing his true intentions. Nasiens then uses his magic to recreate his drug and spread it throughout the gorge, reviving it completely.

Once the misunderstandings are cleared up, everyone there is attacked by a monster that spreads poison over the place crying out for the destruction of Echo Gorge. The monster is revealed to be Ordo, acting under the command of the fairy Nasiens had captured. Nasiens tries to reason with Ordo to no avail, being saved from him by Dolores who ends being hitted by Ordo's poisonous breath. While worrying for Dolores, Nasiens is once again saved from Ordo this time by Percival. When Nasiens asks what he is supossed to do, Percival says that they will bring Ordo back together.

The fairy is later revealed to be a minion controlled by a Holy Knight named Talisker. Nasiens demands that he tell him why he did that to Ordo, to which Talisker says only if he manages to hit him. Nasiens immediately prepares to fight by infusing his weapons with poison, rejecting Percival's help when he is unable to invoke his magic. Talisker then summons a hailstorm from which Nasiens is saved by Percival. However, Nasiens takes a heavy hit from Ordo. Although Percival manages to get in the way and tries to bring him to his senses, Nasiens thinks it is too late. However, a trace of consciousness shows up on Ordo, so Percival protects him from another hailstorm resulting in severe injury.

When Percival manages to confront Talisker by unleashing his magical power, Nasiens hears the story of his conflict with Ordo and how it turned him into a monster. After Percival defeats Talisker and destroys the staff that converted Ordo, the latter returns to normal to the joy of Nasiens.

When Percival, Donny and Sin were about to leave, Nasiens catches up with them saying that he is going with them. When questioned about it, Nasiens tells them that Ordo asked him to travel the world to become a better apotechary than him. Nasiens tries to tell Percival that he is the first friend he has, but ends up saying that he is his first guinea pig. Even so, Percival accepts him into the group to the delight of Nasiens. Saying they need transportation to get to Liones, Nasiens suggests going to Sistana to get it.

Sistana arc
When the group stops to eat, Nasiens experiments with the effects of his poison on Percival's mini golems. After enjoying the food that Percival cooks for them, Nasiens asks him about his grandfather's magical objects and expresses his doubts that they can reach Camelot, a destroyed kingdom, from Liones despite Percival insisting that Sin would not lie to them. After discussing the events that Percival, Donny and Sin went through before meeting Nasiens, the topic of Sin's Incantation Orb comes up for discussion and Nasiens explains what they are and how the magician Merlin created them. He also talks about how Merlin has a book with all the poisons in the world and how he wishes he could see it.

Upon reaching Sistana, a mini golem leads them to find a piece of the Coffin of Eternal Darkness buried. Nasiens shows her interest in her despite not knowing what it is. A girl suddenly arrive and warns them to leave it and to kill them if they intend to give it to "that man".

Although Donny tries to explain that they happened to find it, Anghalhad pulls out his rapier and attacks him, managing to dodge and knock him down quickly. Nasiens says that they have no intention of fighting, but she faces him anyway, managing to overcome him in an exchange of swords. She then demands that Percival give her the piece and to her surprise, the boy kindly gives it to her. A maid appears telling Anghalhad that she must return for the dance that is about to begin. Anghalhad rushes to return the Coffin's piece to Percival demanding that he hide it and not let anyone see it, especially Ironside. She then leaves with her maid.

At night, the four of them stay at an inn. Nasiens explains to them that the girl is the daughter of the Lord of Sistana whom he saw several times during his visits with Ordo. They then spy on Ironside's speech to the townspeople, revealing that he owns the other pieces of the Coffin. Sin reveals to them that Ironside plans to kill everyone in town to activate the Coffin magic. Sin suggests that they escape with the missing piece, but Percival sets out to save Anghalhad when she interrupts the speech. Nasiens, Sin, and Donny run to the inn, but discover the maiden stealing the room, actually being Ironside's familiar in disguise. After meeting with Percival and Anghalhad, Nasiens decides to help them stop Ironside.

During the fight that breaks out with Ironside, Nasiens enchants henbane in Anghalhad's rapier, causing dizziness and shock at Ironside. Ironside unleashes his Belfest Margot, seriously wounding everyone, who is saved thanks to Percival's mini golems who heal their wounds. Ironside, however, captures Percival. Ironside begins to beat up Percival and finally decides to kill him by driving his sword into his heart. Nasiens recovers Percival's body and desperately tries to help him with his drug, but it is useless since Percival is physically dead.

Ironside then intends to continue with the Coffin's ritual, when a breeze of magic leaves Percival's body. Ironside destroys everything to finish it off, being this protected by Nasiens. Ironside points out that he was saved thanks to the fact that his poison affected the precision of his magic and warns him to leave if he does not want to die, attacking him again at his refusal. Percival's magic multiplies more and more, leading Ironside to use his Ragna Claw. However, a revived Percival saves everyone with his magical power, which is revealed to be the power of Hope.

Ironside launches his attacks at him, forcing Percival to fly all over the place to evade them. In that, Donny uses his telekinetic powers to levitate the Coffin away from Ironside, allowing Percival to re-divide it. Ironside claims they haven't stopped him as he just has to kill them and reassemble the Coffin and gather more sacrifices from Britannia. However, another Holy Knight, Mortlach, appears stopping him from continuing the fight and reminds him that whoever destroyed the monsters he summoned must be someone as strong as the Seven Deadly Sins, so in the face of such a threat, it is best for them to retreat.

As everyone twists after the hard battle, Nasiens comments on Percival's cape and helmet that were transformed during the fight. Percival then touches the wound that Ironside left on his back causing him a lot of pain.

The next day, Carden fires them thanking them for what they did. Anghalhad then appears and Percival invites her to join the group.

Cant arc
When the group is forced to stop for Sylvan to rest, Anghalhad then says that it is time to appoint a leader for the group, something Nasiens is not against. Sin then shows a map of Britannia to see the next destination that he suggest to be Cant in order to get supplies to cross Dalflare Range.

Arriving at Cant, Naseisn goes to a forge to get some crystal bottles. Sin scolds everyone for being distracted and that they should first find a place to stay, but Anghalhad end up wasting all their money in expensive stuff, like new clothes for everyone. As Anghalhad and Percival goes to get more money, Nasiens and Donny go to a tavern where they meet Howzer, wich surprises Nasiens to known is Donny's uncle. When Howzer takes the Dragon Handle and the money that Anghalhad and Percival get from gambling, Nasiens challenges him to a drinking contest to win them back. In the middle of it, Nasiens notices by the prices and emblems in the articles that are sold in the town, as well as the presence of so many people who should not live there, that things there are not what it looks like. Edlin appears before Howzer and Nasiens after he deduces that everyone in the tavern is a band of bandits. Howzer reveals that he used to be his apprentice of him alongside Donny but is now the boss of those bandits who are dedicated to stealing their belongings from those who come to the town. Despite having no weapons, Howzer exclaims that they will not be able to defeat him. However, he falls unconscious from drunkenness as Edlin is aware of his weakness to alcohol. Nasiens then unleashes his Misty Rain: Belladonna to poison everyone in the tavern. However, Edlin creates an illusion of Percival by making him believe that he took him hostage. When Nasiens is distracted by seeing the real Percival still passed out in his place, Edlin surprises him by hitting him from behind.

Nasiens is imprisoned along with the others, until Taizoo shows up to free them, where it is revealed that Nasiens used his power to nullify the effects of alcohol during the drinking competition. There, the group discovers a hidden baby dragon, which is the baby of the dragon that was causing chaos outside. Nasiens notices how weak the baby is and that he will die in at least three days, so she decides to give him medicine. After hestiating about helping Edlin, Howzer finally decides to act and asks Nasiens to use his magic to remove the alcohol from his body.

Nasiens arrives at Sin's side after Howzer defeated the dragon, having cured the baby and returning it to its mother.

Dalflare Range arc
As the group heads up the mountains, Nasiens have trouble to keep the peace, specially hearing that are still four days of travel. Camping for the night, Anghalhad asks Sin why this place is called the Dark Range. Sin tells him that there are stories that spiritual powers there show visions of your future self or possible lovers and there are also tribes of man-eating ogres and dimensional caverns with no escape.

The next day they find a strange town where Sin feels a magical presence.A hunter named Ardd warns them that this place is a dangerous nest of monsters, but not before Percvial, Donny and Sin get into it. Anghalhad and Nasiens learn from Ardd that this village appeared out of nowhere recently and that its residents turn into monsters when they leave it. Hearing that no one who goes in comes back out, Anghalhad insists on going to look for his companions, asking Ardd to tell them how to help them. The three formulate a plan for Anghalhad to destroy the idol in the center of the village while Ardd distracts the villagers so Nasiens can search for his companions. When Nasiens questions Ardd's willingness to help them, Anghalhad confirms that he has not lied.

Upon finding Donny appareantly hurt, Nasiens go to help him while Anghalhad goes ahead. Donny is revealed to only have a bad reaction to the drink, the two then are surprised to see Percival talking to a boy in a strange language he has never heard before. After destroying the idol, the villagers are revealed to be demons. Anghalhad and Sylvan run away terrified thinking they will be eaten, taking a shock when Percvial, Nasiens and Donny are with one who turns out to be friendly. As the Elder of the village explains that now the barrier that protects the place is gone, the enemy is able to enter, Ardd suddenly appears revealing himself to be Ardbeg, a Holy Knight of Camelot, and locks up all the demons of the village in an Amber of the Four Archangels, despite the Elder trying to explain that the demons of the village are deserters who refused to fight in the Holy War.

When Percival is forced to fight the beast Cernunnos, Nasiens uses his Mysty Rain: Belladonna to finally knock out the creature. Ardbeg flees to the Crystal Grotto, where he manages to evade Percival's group and have enough time to use his magical power, Reverse, to turn them into babies. When the Elder appears and reveals his identity as Gowther the Goat's Sin of Lust, he prevents Ardbeg from going ahead with his plans.

When everyone returns to normal, Anghalhad shudders to see that they are all naked. Wondering what happened to Ardbeg, Gowther offers to explain, leaving them confused as to his identity. Back at the village, Nasiens is pleased to recieve a bit of Cernunnos's antlers, wich Dolchomonte comments is useful for making medicine.

Leaving, Nasiens tries to comfort Anghalhad, depressed over Ardbeg's death, by telling her that he saw his deceased daughter in her. Upon reachin the Entangled Forest, Sin and then Anghalhad suggest to lure their pursuers there but the girl lacks of any idea of how to do it.

Entangled Forest arc
Upon fooling the Dark Talismans using Percival's mini golems to separate them, the group prepare to ambush each one individually since Sin says that they have no chance otherwise. Elgin is the first to be ambushed. He demands to know which of them is Percival, he shows up being blocked by his companions. Determined to eliminate him, Elgin quickly shoves Anghalhad and Nasiens out of the way, sending them tumbling into the void. Elgin threatens Donny telling him to give him ten seconds to run away, but Donny refuses using his magic to float Anghalhad and Nasiens. The four then attack Elgin at the same time with his weapons, although he manages to avoid the damage. Elgin praises Nasiens's intelligence, as well as their combo. Saying that they dug his graves when facing him alone in that place, Elgin throws his Epicurean's Slaver and after sticking his sword in the branch that everyone was on, it begins to shatter. Nasiens enchants his and Anghalhad's weapon to prevent being affected, and Donny manages to use his magic to hold it, but Elgin does great damage to him and Percival with a few small blows. Nasiens notices the debilitating properties of his magic, Wither.

Elgin then attacks him with his sword and manages to give him a big punch. However, Nasiens reveals to have nullified the effects of his magic thanks to the drug he made with the horn of Cernunnos. Nasiens then throws his Misty Rain on Elgin. He claims that he cannot evade him in such a tight space, but Nasiens manages to cut his sword and arm with his weapons. Asked how Nasiens managed to mimic the effects of his magic, Percival reveals that Nasiens can replicate whatever poison they use against him, just before giving Elgin a big slash with his sword.

As they regroup, Nasiens suffers from the side effects of his drug, leaving him very weak. the group advences trought the forest flying in Percival's aura. However, they are pursued by Doronach and Burgie thanks to their flying horse, Sleipnir. Burgie attacks them with her Wind Sickles and then cuts them off with Sand Wall. As Anghalhad and Donny decide to confront them, and manages to win thanks to Sin's advice.

When Fiddich arrives and criticizes the performance of his companions, he declares that he no longer intends to eliminate Percival and the rest without pain, but to give them a painful death and in desperation for humiliating them. Once Elgin joins them, Fiddich uses an Incantation Orb to heal his teammates' injuries with a Hyper Recovery Spell. Losing all hope, Nasiens laments that he could never become the aphotecary he dreamed off, but Sin and Percival manage to raise everyone's morale to continue fighting.

As Fiddich indicates his fellow Talismans to eliminate Sin first, who acts as their commander, he locks the four with Sin in a Perfect Cube so that the others do not interfere. However, this backfired as Sin returned to his true form, revealing himself to be Lancelot, and taking down the Dark Talismans one after another. Seeing who he really is, Nasiens suggest for his transformation and mind reading abilities if he is a member of the Fairy Clan. Lancelot uses some arrows to make three graves for the deceased Elgin, Doronach and Burgie, explaining as he buries them that he is a servant of the king of Liones, sent in order to find the potential Four Knights of Apocalypse and bring them and their companions to the kingdom guiding and protecting them without interfering too much in order to see if the prophesied knights had the will to overcome the obstacles that came their way. Thus, he disguised himself as a fox so that the Holy Knights of Camelot would not discover him.

When Pellegarde appears, Lancelot says they do not have time to play with him and uses an Incantation Orb to teleport away leaving Pellegarde with the words in the mouth. The group suddenly appears in the Kingdom of Liones, and Lancelot says that the king is waiting for them.

Chaos in Liones arc
As they roam the streets of the kingdom, Anghalhad gets excited to see real Holy Knights leading Donny to mock their attitude. Arriving at the castle, Anghalhad is nervous to see her idol, Meliodas, but is disappointed to learn that she is out partying.

Seeing that Percival separated from them, Lancelot asks the rest to go find him. they eventually find him being attacked by the Tristan Platoon, so the three of them promptly get up to intervene. However, Chion's Sylph suffocates them and leaves them vulnerable to Isolde hitting them with her morning star, leaving them in serious condition. After Tristan knocks a berserker Percival down with his swords, his three friends rise to shield Percival and leave everyone shocked when they manage to bring Percival back to his senses.

Tristan then uses his magic to heal Percival's friends, but is unable to reverse the mummification of Chion's arm. Anghalhad and the others defends Percival when Chion blames him, until Percival manages to heal him himself. When Lancelot arrives telling that the fourth Knight of Apocalypse had fleed the scene. Lancelot orders Tristan's party and Percival's party to check the east and west gates while he himself checks the south gate.

As they search, the four discuss their recent experiences and whether this fourth knight is really trustworthy. When Percival thanks them for saving him earlier, the group has an emotional moment.

The group encounters a man fighting a Holy Knight, whom they initially believe to be Gawain, but who is revealed to be Pellegarde. Upon getting engulfed in the fire of Pellegarde's power, Nasiens is protected along everyone else by Percival's power. Anghalhad along with Nasiens and Donny watch as the Four Knights of Apocalypse gather and urge them to end the fight, but are alarmed when Percival is kidnapped after trying to reason with Pellegarde. Lancelot then goes to the castle telling the three of them to wait there for Percival and the others to return.

The three then rush to where Percival and the rest were fighting Chaos Galand and Chaos Melascula, but arrive after they have already been defeated. As all the Holy Knights present offer their full service to the Four Knights of the Apocalypse, Anghalhad and Nasiens realize that Percival is an existence far beyond them.

When the two demons merge in Melagaland, Anghalhad watches the fight alongside Nasiens and Donny. When Gawain faints from draining her magic, Nasiens is shocked to see that her true form is that of a little girl. In between, everyone seems to be suffering from some sort of disorientation. Hendrickson arrives and explains to Nasiens that this is due to a neurotoxin that affects their sense of distance, something he noticed by chance when he saw how it affected the birds of his clinic, so they all need to be vaccinated. However, Nasiens uses his power to spread a makeshift vaccine which leaves Hendrickson impressed. Hendrickson attempts to shield Nasiens from Melagaland's attack, but the two are saved by Dreyfus.

The night after the battle, Anghalhad is upset when Percival, Nasiens, and Donny insist on staying in the same room as her. When Percival is depressed for his weakness, Nasiens tries to cheer him up saying that he saved them all during the battle.

Current arc
The day after the battle, Nasiens visits Hendrickson at his clinic, marveling at the materials he has like the demon world snake, asking him where he can get them. Hendrickson explains that the king usually takes them as souvenirs and in return he helps him with the royal store. Hendrickson comments on how impressive his Mix Venom power is, seeing it as a sign that he is destined to master medicine and pharmacy, especially coupled with his abundant curiosity. When Nasiens tells him that his teacher Ordo sent him to the world to learn, Hendrickson offers him to work with him at his clinic. However, Nasiens says that he can't because he must help Percival on his journey. Hendrickson reminds him that not being a Holy Knight, he will surely end up being more of a burden than a help.

Nasiens is then called to an audience with the king along with Percival, Anghalhad and Donny. Already in the castle they are received by Queen Elizabeth, leaving Nasiens surprised by the resemblance with her son Tristan. When Meliodas appears groping Elizabeth's breasts, the three are surprised to find out that he is in fact the king, as Nasiens first believe that he was Tristan's younger brother. Although Meliodas thanks them for everything they have done so far, the three of them are sad. When Meliodas tells them that it is time to say goodbye, Nasiens explains to Percival that they are not Holy Knights nor do they have the strength to fight alongside him. Though Percival pleads with them not to part, they tearfully deny him, as Nasiens wishes he could have traveled with him more. However, Meliodas interrupts them saying that they misunderstood him and to everyone's surprise, he officially appoints Nasiens, Donny and Anghalhad Holy Knights and asks them to continue helping Percival. They ask why he told them to say goodbye, to which Meliodas explains that he meant to say goodbye to their old lives until the war with Camelot was over. Meliodas apologizes to them for leaving the fate of the world in their hands, but he tells them that he is counting on them to help him protect Britannia. Despite happily accepting, everyone is furious at being tricked.

As he takes in being made a Holy Knight so untimely, Nasiens thinks it's more than he could have hoped for but is overjoyed at being a knight of the Percival Platoon. Meliodas then leads the new formed Percival Platoon to the war room where the other members of the Four Knights of Apocalyse and the Tristan Platoon were gathered to discuss the situation with Camelot. When Anghalhad ask why are they fighting a kingdom that was destroyed 16 years ago, Thetis explains that Camelot was recreated in an alternate dimension by the power of Chaos but are now starting this war because there is a price to pay in order to rebuilt and maintain the new Camelot. To further expose her words, she uses her magic to teleport everyone to a landscape that has been stripped of various parts, leaving only empty spaces. Meliodas explain that it is the result of Arthur creating a new Camelot, something he heard from Percival's grandfather who was a former Holy Knight of Camelot. Chion says that they not only have a relative of Arthur but also a pipsqueak from Camelot, which further undermines his confidence, leading Nasiens to defend Percival by claiming that his birthplace doesn't matter. When everyone is left despairing that they have no way to get to Camelot, Nasiens and the others are shocked when Percival suggests they go on an adventure together to find a solution.

Nasiens is affected when he sees Percival with his head on Anghalhad's breasts. When the Percival Platoon recieves their new outfits, Nasiens is still affected altought he delights by his new clothes.

On the day that everyone will finally set off in search of a way to Camelot, Meliodas divides the Four Knights into search teams. The Percival Platoon is appointed to the Fairy King's Forest.

After leaving, the group arrives at Wallnack deciding to all stay there one night before splitting up in Dalmary. As everyone decides how to split up the inn's rooms, Nasiens ends up sharing a room with Donny and Jade. There, when the three of them were talking, Nasiens comments that Jade has feelings for Isolde, which he embarrassedly acknowledges but takes away from its meaning since Isolde is in love with Tristan, although Nasiens says that there is nothing wrong with liking her even so. Jade then says that Nasiens has a crush on "the shorty", leaving Nasiens very upset. However, Chion reveals that he is referring to Anghalhad, to which Nasiens concedes with some relief, despite Donny scoffing that he likes a stubborn stuck-up girl.

Abilities

 * This power enables Nasiens to ingest any kind of poison and "teach" its composition to his body, letting him create his own mix.
 * Anghalhad, Nasiens, Percival and Donny each attack a single opponent with their swords.

Weapons
Nasiens dual-wields the dagger and the shortsword.