Chapter 16: Chapter 15

"You'll understand when I finish my story. where was I, right Avengers defeat. So after he was defeated he returned to the grail, however rather then returning to the throne of heroes he stayed in the grail, just like his legend. You see, unlike what the world believes Angra Mainyu was originally a simple farm boy. Unfortunately fate was cruel, he was chosen by his village as the 'source of all evil in the world'. That was the beginning of his hell, every day he was torture, abused, cursed and shund by all, they believed that by blaming him for all the evil in the world it would absolve them of all evil and purify them selves. So they tortured him his whole life doing all manner of cruelty to him and carving all manner of evils and curse into his flesh and defiling his mind. However they never allowed him to die, doing everything they could to keep him alive till he naturally died of old age, however that wasn't the end. As one final act of cruelty they cursed him forever after his death, one using the great evil he was to represent. So after his death rather then die he remained as a pseudo Divine spirit, stuck in the world and unable to interact with it, cursed to wonder for all his afterlife. However these same actions also qualified his as a heroic spirit, normally he could never be summoned though, however the Einzbern actions, circumvented the grails security system's and allowed him to be summoned. But not the pseudo Divine spirit that they expect, rather the poor tortured farm boy he was in life. After his defeat he kept in line with his legend and remained in the grail, corrupting it, defiling it, turning it into a mockery of what it was. Now to answer your question about Justeaze, she sacrificed herself as the core of the greater grail, in order to allow someone to truly obtain the third magic. You see Justeaze was the Einzbern's ultimate creating capable of wielding the third magic however it wasn't perfect. Unlike you who has completely obtained your magic, you can freely unleash it's miracle at will, as most if it is powered directly by the root, an example it me. You took my soul from the grail and created a body. For any magus no matter how good, even if they new exactly what and how to do it and had all material recourses ready, they still couldn't because of the lack of mana, even the grail doesn't have enough mana to power such a miracle, unless the person in question was using the third magic even if only a fragment"