[Chaos]

No one thinks the issue here might be Spellthief?

Spellthief is a major issue when it comes to piling on powerful support spells, thanks to the ability to grab Malmelo/Death Knighting/(Elemental Enchant spell here) and whatever other support spells the user desires in one easy, evade-friendly package.

While limiting Spellthieves on this front (see: either require Destiny for these kinds of spells, or prevent support spells from being used entirely) would help immensely, we should also recognize that the damage was possible due to the multiplicative nature of percentage damage boosts, and that if Spellthief was swapped out for Hexer, Joker wouldn't have lost the all-important boosts from Redgull and Death Knighting.

In other words: Spellthief is part of the problem, but not the decisive factor.