Abaddon is a 10,000yro demon trapped in the body of a 9yro boy from the 1700s. Despite this, he is very childish, which means he would often throw temper tantrums when things don't go his way, and sometimes he would cry over hurting himself, even though he can handle chopped off limbs. He is prone to tunnel vision, focusing on one task to another. A thing about him is, he only demands the needs he himself wants and never his vessel's. That means he would deny urgent body needs even when it's obvious, so Katherine has to force him.
Childlike and explosive—starts big, derails into sing-song bursts, then sulks abruptly.
