Spell of Soul-eating

Spell of Soul-eating (식혼의 주술, Sighon-ui Jusul) is a forbidden spell that used to makes many people to become one by eating each others souls. Hoaqin found this spell that was left by an ancient demon, and studied it with his siblings. In the end they succeed in becoming one, and lived for countless years in one body. This spell caused all of them become one entity called White. However Hoaqin was the only one who actually made a deal with the demon.

After White ended up defeated by Zahard's Princess, the spell was broken and they back to their original form. White was driven out of the slayer position and lost his power. He boarded the Hell Express to absorb souls and be the slayer he once was again, so he has already put a spell that will make the tremendous power of all those spirits his. But for some reason, he was trapped in that place and can't get out of the train before he become the complete one, because of the contract that he made with Administrator. They needed a lot of "sacrifices" to do it, but they failed and were sealed in an unstable condition. If he completed his form and activates the spell, every single creatures and spirit in the train will be prey for him. He will be able to kill the living and raise the dead.

However the moment when his goal almost achieved, his plan ended in vain because of Roen sacrifice. She successfully completed the spell to sacrifice her own soul, in order to seal him off forever.