Alioni is a young man with light-colored hair, donning a set of pitch black armor and a cape attached with the emblem of the Holy Knights.
Alioni is cruel and insane, willing to kill his companions if they failed him.
Not much is known about Alioni's history.
Alioni is at his castle where a poor farmer begs for his sister to be freed, as she was chosen to be his companion, when the Holy Knight decides to kill him after being slightly irritated. The three knights who were sent away by Meliodas at Avallo are commanded to recite the definition of a Holy Knight, leading Alioni furiously angered, knowing that they have embarrassed him.
He heads towards Avallo, breaking in by destroying the wall, to discover who defeated his knights. He discovers Elizabeth, realizing that she was the wanted fugitive and former princess, before preparing to make the pair disappear. He commands a party of knights towards them, when Meliodas easily knocks them away with his bare fists and questions whether Alioni harmed his own subordinates. Alioni states his disapproval to worry about his companions, which Meliodas quickly rebukes him, declaring that a true knight are guardians who should protect their comrades, people, promises and principles. Laughing at Meliodas, Alioni delivers a wide slash, damaging all of the furniture, when unsheathes his gigantic sword from the ground and reveals his identity as the captain of the Seven Deadly Sins. Alioni begins anxiously sending a series of random attacks with all of them being parried. With a single thrust, Alioni is blow away by Meliodas, flying across mountains with his knights following after him.
Alioni carries a long sword.
As a Holy Knight, Alioni is very powerful and could have the power of a country army like any other Holy Knight, but Alioni wasn't strong enough to face Meliodas.
- Meliodas vs. Alioni: Lose
- Alioni is the only Holy Knight to appear in the Oneshot series.