Questions about the history of heroes.

Isabelle vowed to avenge the "treacherous murderer, Agrael," but it's not entirely clear whether she knew he had killed her husband or if it was some abstract demon, and she was only going to avenge Beatrice. The latter is more likely. It's as if the queen had never encountered necromancers and the fruits of their activities before. But Marcel, of course, tried his best and turned the king into a puppet for himself, rather than a sane husband for Isabelle.