Mortlach

is a Holy Knight serving King Arthur Pendragon of Camelot. He is also the brother-in-law of Ironside and the uncle of Diodra.

Personality
Mortlach has shown himself as someone who cares about his family, his older sister, brother-in-law, Ironside and nephew, Diodra. After the unfortunate death of his sister, Diodra, became his "shining light", being lighthearted and casual around him, sharing stories about him and his sister, and aiding him in sword training. He shows this side of himself around the more serious Ironside, once calming him down and convinced him to not continue fighting against Percival and the others after the ritual involving the Coffin of Eternal Darkness failed.

As a Kingdom of Camelot, Mortlach is hostile towards the For Knights of the Apocalypse, who would end Arthur and end his Eternal Kingdom, which would mean he Diodra wouldn't lose his means of recovering from the Demon King's poison. However, same as Ironside, he is most hostile to Percival, openly declaring that the young man is deserving of "punishment" both of them believes he deserves. After revealing the truth of his birth, Mortlach's hatred and vindictiveness is shown as he declared Pervical didn't belong to the five races, as well as not being Ironside's son, let alone being Varghese's grandson, placing the blame of his brother-in-law's despair and declaring him a threat to the everyone.

History
Mortlach lived almost all of his youth with his older sister, who raised him after the death of their mother and their father becoming an abusive alcoholic.

Mortlach was happy when his sister married a renegade Holy Knight named Ironside and became pregnant. However, she fell ill from the poison released by the Demon King during the new Holy War, which led to her death despite all the treatments she received.

When the baby she left behind, Diodra, began to suffer from the same illness, Ironside took him back to the kingdom of Camelot where Diodra was saved thanks to the protection of the Chaotic power. Mortlach, along with Ironside, became Holy Knights in the service of Arthur Pendragon in order to protect the child.

Mortlach, along with Varghese, witnessed Ironside use a forbidden spell to transfer a Life Spirit into the body of a dead baby, Percival, in order to turn him into a vessel for Diodra.

Sistana arc
Mortlach appears in the middle of the battle between Ironside and Percival's group. Mortlach stops Ironside from continuing the fight, Ironside demands that he not interfere, but Mortlach 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. After collecting the pieces of the Coffin of Eternal Darkness minus the Dragon Handle that Donny kept, both Holy Knights leave.

Wallnack arc
Mortlach was training Diodra with swords, surprised by his nephew's progress and asking him if he was training alone in secret. Diodra asks him not to tell her father so as not to worry him, to which Mortlach says that Ironside will end up scolding him. Diodra then asks him to continue telling his story, and Mortlach tells him about when he and his sister were punished by his father for sneaking out drinking and gambling, warning the boy not to do the same. Diodra asks him why his father keeps telling him lies that Britannia is nothing more than a world full of dangers, further fueling his curiosity. Mortlach tells him that he understands what he feels, but that her brother-in-law does not lie and that he is sure that he loves him from the bottom of his heart.

When a bird arrives to inform Mortlach of a mission from king Arthur, he leaves, leaving Diodra in charge of Turret and Rothes.

Demon Realm arc
Mortlach and his fellow Holy Knights track down the Four Knights of Apocalypse, finding them when they cross the entrance to the portal into the Demon Realm. Deciding to follow them, they end up being thrown into the void by the relic that connects them to the Demon Realm, saving themselves from the fall by summoning an Arakdo that takes them flying.

Meeting to decide how to proceed, Mortlach notices something strange about Rosebank when she refuses to speak, claiming to have been infected with the Demon Realm's miasma. Confirming with his other companions, Mortlach attacks Rosebank, who ends up revealing herself to be an illusion created by Gawain.

After trapping his companions in her Super Slow spell, Gawain asks Mortlach to tell Arthur to leave her alone. Mortlach tells her that there is still time for her to return and beg his forgiveness, but Gawain removes his helmet with a magic beam, stating that she does not beg anyone.

Mortlach then tells her that despite being "commoners", they all have someone they love and for whom they would give their lives, something that Gawain cannot understand since she never felt love for anyone, not even the father who raised her or his uncle who gave her everything. Gawain reacts annoyed, stating that she never got what she wanted in Camelot, answers to who she is, who gave birth to her, why she can't feel love for anyone and only be interested in women. Mortlach says that she joined the Four Knights because she believed that by fighting alongside those like her, she could find those answers. Gawain rages at his taunts, not noticing the knight who surprises her behind her and knocks her out with one blow.

Mortlach and the rest then happily greet the real Rosebank, relieved that she is safe. Showing her a captured Gawain, Mortlach reminds everyone that they cannot kill her because she is the niece of their king. When the group finds itself unable to do anything but wait for the enemy, Mortlach says that they are in no rush since they already know the enemy and its strength, and that the best way to stop the prophecy is to take out Percival, who is below Tristan and Lancelot.

After a week, the Four Knights head to the Behemoth area inside an Albion. Mortalch and the rest follow in their Arakdo, using the Saint Coat to ward off the Behemoth's growing negative force. The group manages to get on the Albion, pretending to wait for the enemy to reach their destination and then defeat them to thwart their invasion of Camelot. However, Lancelot manages to detect them and uses the Albion to attack them. Mortlach then orders the Arakdo to destroy the Albion, commenting that not even an Albion can match it. Although the Arakdo manages to take down the Albion, Mortalch is surprised to see how it is easily destroyed by Lancelot when he orders him to eliminate them all.

When the two groups confront each other, the Behemoth's negative energy begins to kill the Cahos Knights while the Knights of Apocalypse are protected by Percival's power. Seeing no other way out, Mortlach pulls Gawain and Schwarz's group out of a cube, using them as hostages to force Percival to save them and the Chaos Knights as well.

When Percival manages to put the Behemoth back to sleep, Mortlach comments that what his brother-in-law told him about the child was true.

Mortlach then challenges Percival to a one-on-one fight, though Rosebank tries to convince him to talk things out because Percival saved her life, but Mortlach insists that they must fulfill their mission to end the prophecy to protect what they hold dear.

When Percival accepts the challenge, Rosebank is quick to return the Dragon Handle, which annoys Mortlach before both he and Percival are sucked into a dueling chamber in another dimension. After explaining how his Duelist power works and a quick exchange of swords, Mortlach says that he knows the truth behind Percival's origin and that is why he must eliminate him before he becomes something truly fearsome. Percival tells him that then he will make him tell him what he knows, but first he asks him about the statue that supposedly represents the person Mortlach values ​​most, questioning if that person knows about all the damage he is causing to Britannia and the other clans.

Mortlach reveals that person is Diodra, his nephew and son of Percival's father, who suffers from a poisoning that he can only survive thanks to the protection of Camelot. Mortlach declares that they are the ones who are trying to take away Diodra's only place and his very life. Percival shares his sentiment but says that he must still stop Arthur and help his friends. Mortlach continues the fight, declaring that they have no other way out, although Percival says that there must be a way to resolve it without having to fight. Mortlach then uses Thousan Cross, an attack that not even Ironside could defend against. Percival however, is able to block it, not once but twice. Mortlach does not understand how this can be possible if he was previously unable to handle Ironside, which Percival reveals to be the result of his training with Lancelot. Percival then manages to land a clean hit on Mortlach, going far enough to incapacitate him and undo his Duelist power from him.

Back in the Demon Realm, Percival demands that Mortlach tell him what he knows about his origins. There, Mortlach reveals the truth of how Ironside created him by transferring a Life Spirit into a dead human vessel in an attempt to save Diodra, making Percival a being who should never have been born into this world. When Percival suddenly falls to the ground lifeless, Lancelot asks Mortlach what he did. He says that Percival simply vanished because he could not bear the crime of his existence. This leads a furious Lancelot to kill Mortlach with his katana.

Abilities/Equipment
As a high-class Holy Knight, Mortlach is a strong warrior. Ironside, who is a powerful Holy Knight in his own right, admits that Mortlach is superior to him at sword fighting.

Abilities

 * This power allows Mortlach to lock himself and whoever agrees to a duel with him in a pocket dimension or "dueling chamber" until a winner emerge.


 * An extremely fast attack in which Mortlach circles the opponent creating afterimages, slashing them with his sword in a quick succession.

Weapons
Sword: Mortlach carries a cutlass on him at all times.

Percival
He shares the same views Ironside does about Percival, seeing him as threat to the Camelot, and thus a threat to Diodra's continued treatment in the medical aid due being inflicted with the Demon King's poison. Despite this, he is still capable of acting his usual calm manner in front of Ironside and even reminding him about their purpose. Meeting Percival in the Demon Realm, Mortlach openly declared that he deserved all the punishment that either he or Ironside would inflict upon him. Same as Ironside, he gravely underestimated Percival, who was incapable of using magic in the Duelist space resulting in his defeat.

Upholding the promise, Mortlach informed Percival about the truth behind his birth, but doing so in the most vindictive and hurtful manner possible. Same as Ironside, his desire for Diodra to live bordered on obsessive, almost considering using forbidden spells and unethical methods to transfer his nephew's soul into the body of a deceased prince's vessel named Percival, imbued with a powerful Life Spirit, who was without self-awareness. However, because Varghese stole Percival, who would soon develop awareness of his own, it made it impossible for him to be a vessel. Finally, declaring Percival wasn't anything or anyone, not a member of the five races, not a member of his family, and that he should've have been born.

Trivia

 * Like many of the Camelot Holy Knights, Mortlach is named after the, a distiller of Scotch whisky in Dufftown, Moray, Scotland, founded in 1823.