Does V-tweaks allow me to blacklist mobs that can be converted into "Pyro -" your mod is currently conflicting with another.

https://minecraft.curseforge.com/projects/tf2-stuff-mod/issues/10

That should be totally do-able. Give me some time and hopefully by tomorrow I'll have an update for all 3 versions of Minecraft (1.10.2, 1.11.2 and 1.12) adding a Blacklist list which you can add entities which will not become Challengers. Thanks for pointing this out, this is actually a really obvious feature I should've thought about sooner.

Fantastic! Thank you for a great mod :)