As the Knight of death with a thirst for blood, Elesis swallows blood to enhance her destructive powers to eliminate her enemies.
The intent to kill, and thirst for blood is instinctual. Her body, used to utilizing demonic energy has become corrupt irrevocably. Realizing that there's only one path she can take, she transforms in to the Knight of Death, 'Bloody Queen,' who slaughters any demons that comes in her way.