Here's the crash log I alluded to in the comment.

https://imgur.com/JjEYbH5

The crash comes from the Spire Biome, specifically the Biome with the Storm effect that, in the line of code from what I understand, has something to do with how the damage is applied to the character and how this mod interacts with said damage. It doesn't matter if it's the player or enemy, it will crash regardless and it's easy to replicate consistently.

This can only happen with a character mod "Pokemon Master" where one of the mechanics of the character "Burn" also does abstract damage and causes the game to crash with a similar log.

Hope that helps

Pushed a possible fix.

Interacts with the N'loth event (swap this mod's relic for higher chance of rare cards), so it can be unfair.
Thx for the mod btw!