Ruin

"Hey, Ruuuin... wouldn't it be bad if we killed the princess? Fwah fwah, there's nothing quite like a little girl's face writhing in pain."

- Friesia and Ruin about him severely wounding Elizabeth in Dedicated Resolution

is a Holy Knight belonging to the infamous Weird Fangs stationed at Baste Dungeon. He aided in the capture of the Deadly Sin, Ban 5 years ago.

Appearance
Nothing of Ruin's facial appearance is known, as his face is covered by a helmet. Ruin is a fairly large and tall man, towering over normal sized people.

Armor
Ruin's helm looks like a feminine human face with white eyes and long hair with 22 holes on both sides of the helmet. He has black shoulder plates that curves inward, a flower design on his breast plate, a long black skirt that reach to the floor, and metal boots. Beneath his armor, he is shown to have a well-developed rectus abdominis muscle.

Personality
Ruin is cruel and manipulative, laughing as he injures a unarmed and helpless person. He also enjoys to see the face of a young girl writhing in pain. Despite that, Ruin has some sense of honor as he commended Elizabeth's bravery after witnessing her selfless act to go through Friesia's deadly attack to save a child, who actually is himself in disguise.

5 years ago
Five years before the beginning of the series, Ruin and the three other members of the Weird Fangs confronted Ban  of the Seven Deadly Sins. The resulting battle ended in Ban's capture and imprisonment in Baste Dungeon, where Ruin remained as one of the dungeon's four guardians.

Forest of White Dreams arc
The guards that are guarding Ban mention that he along with the Weird Fangs are at the Baste Dungeon.

Baste Dungeon
Ruin is first seen inside the Baste Dungeon, along with the rest of the Weird Fangs, listening to Friesia informing them that he is going to launch the first offensive and kill both Meliodas and Diane. Later, after him and Friesia have finished getting ready to fight the Deadly Sins, the both encounter Golgius when he returns to the Baste Dungeon.

As Diane is heading for the Baste Dungeon, Ruin, having disguised himself as a young shepherd, hypnotizes her into thinking Meliodas was him, thus making her attack her captain. While Meliodas and Elizabeth flee from her, he, under the same disguise, and now accompanied by a knight also disguising himself as a shepherd, pretend to be ordinary humans, leading the two to hide him and the knight along with them, allowing him to hypnotize Meliodas also. Later, as Elizabeth protects him from Friesia's attack, believing him to be a child due to the disguise, he reveals himself to her. He then starts to heavily wound Elizabeth, explaining that even though risking her life to protect a child was admirable, the reality was harsh, as she tries to make him stop his hypnosis. Just as he tells the princess about the original of his powers, which is the bell on his staff, he notices that is is gone and then realizes that Elizabeth was aiming to removing it all along. In anger, the Holy Knight tries to kill her, but Meliodas, having regained his senses as Ruin's hypnosis has been stopped, stops him.

As Meliodas tells Elizabeth that he accepts her resolution, Ruin, saying that the one who strikes first, wins, attacks Meliodas with his staff. While Meliodas was still flying from the hit, Ruin hits him again with his staff pinning him to the ground, commenting that the former had lost his edge since he showed his back to his enemy. The Holy Knight then grabs Meliodas's head and lifted him, stating that he finds it ridiculous that the kingdom was afraid of a small child. However, just then, Meliodas punches him, and then punches him again, sending him crashing into the walls of the Baste Dungeon, much to the surprise and shock of the guards stationed there. Ruin, seeming to be uninjured, comments it would have been boring if Meliodas wasn't as strong as this. He, explains that Holy Knights are called so because they have magic that transcends human knowledge imbued into their bodies, and then suggests that Meliodas draw his sword, since his childlike and soft first wouldn't even scratch his armor. Ruin, seeing the young man wouldn't draw his sword, starts punching him with tremendous power, which causes the whole of Baste Dungeon to shake. Ruin thinks he crushed him beyond recognition, but Meliodas punches him back in the chest, therefore breaking his armor in that area. Though Ruin then says that his armor is nothing more than shallow skin and his body, which is stronger than steel, is his true armor, Meliodas punches him again, but with so much power that his entire hand goes inside the Holy Knight's body, which makes the latter spit blood from his helm, thus defeating him. Ruin was sent flying into the dungeon, destroying large sections of the prison and left for dead.

Abilities/Equipment
Ruin like all other Holy Knights have magic imbued within their bodies. Ruin is a strong fighter as he was able to defeat Ban of the Seven Deadly Sins along with the other Weird Fangs including managing to strike and pin down Meliodas with brute strength causing the ground to crack under the pressure of his blow. He is also able to hypnotize his opponent through illusions by using his staff's bell. Though is also capable of strengthening his skin, which he claims to be stronger than steel and to be his true armor, he was powerless against Meliodas.

Weapons
He wields a circular staff which has a bell hanging at the center of the ring shaped head.

Abilities

 * Illusions: Ruin is capable of creating illusions and causing potential hypnotism to deceive individuals. His powers are fairly strong as they are even able to delude even Meliodas and Diane.

Friesia
Ruin and Friesia are both members of the Weird Fangs. Friesia calls him an "old man".

Golgius
Ruin and Golgius are members of the Weird Fangs.

Jude
Ruin and Jude are members of the Weird Fangs.

Baste Dungeon arc

 * Meliodas vs. Ruin: Loss

Trivia

 * Ruin has a unique laugh, Fwah Fwah.
 * The black skirt Ruin wears is akin to the kilt traditionally worn by the people of Scotland.