NHF – new heroes for Heroes V 3.1.

What about the idea of improving the quality of loot from treasure chests? For example, more creatures, resources, and better artifacts.

Yes, all of this can be done. The main thing is to avoid problems like the one with Falmer. Special abilities that override events for all heroes are not very good: they can negatively affect others at any moment. That's why I initially didn't want to make Eymund like that.
Can you give a specific example?