@listelian Ah! I'm not familiar with the reference, I confess.

My instinct is that Chara must have adored their new father, so strong yet so gentle, and so it would have hurt all the more to feel that Asgore was trying to force them into a role they didn't fit. Their old parents did that but they could _hate_ their parents. How could Chara hate Asgore? That's one reason, I imagine, they resorted to flight. (again, all personal mythology here XD forgive me)