Agasha Ichiro

Agasha Ichiro was a child doomed when by happenstance summoned an oni.

Family
Ichiro was the son of Agasha Dorachi, a Dragon scholar.

Summon Oni
Ichiro was ten years old when he tried out his father's spell scrolls. He foolishly summoned an oni, which took his name, Ichiro no Oni, and boound Ichiro's spirit to its own.

Maho-tsukai
Ichiro cursed his family, killing them so he remained the sole heir. He also cursed many of the castle's potions causing chaos.