Baron Von Bracken has two million health if you're fighting with max level wizards. On lower tiers, this boss still has a huge amount of health. I'm not here to complain about the health, which I think is fine and this kind of fight is fun to have occasionally. But the problem I do want to point out is that this boss is the one that drops Pigsie Spellements.
Because of the nature of this boss, this fight takes longer on average to complete than the other key bosses. Which means slower acquisition of Wysteria Spellements. I bring up Pigsie in particular because Pigsie is perhaps the only Lore Spell that people may want on multiple wizards for practical reasons. Every school except Fire and Storm (and then, maybe also those schools, if they want to I suppose) would want Pigsie in case they ever have to play as the healer in a battle. And because of this, people would want to farm for max-tier Pigsie on multiple characters rather than just one of them.
I think that this combined with Baron Von Bracken taking longer than other key bosses is a bad choice. I'm wondering if this boss's mechanics could be given to a different boss, perhaps one coming up in the future, and remake the Baron Von Bracken fight so that its completion time is similar to the other key bosses.