As it looks now, damage UVs are considered pretty worthless. I'm not saying my idea would make them as desireable as ASI or CTR, but I believe it would be pretty nice if damage UVs would affect two kinds of enemies, divided by the damage types they inflict. Undead and Fiend UVs would be converted into a single type of UV which has effect against both enemies, same for Gremlins/Constructs and Beasts/Slimes.
This could also be applied to some gear and weapons with inherent damage bonuses against monster families, such as Deadshot, Cold Iron Vanquisher, etc. Perhaps not all of them, though.
I don't know about this, I would rather have it so that each type of bonus is unaffected by other bonuses (while stackable each type is not capped by the bonuses of another)
For example a Skolver set with BTS would have max sword damage (+6) and a DA with UV undead VH (+4) with a Ghostbuster 3 (+3) would instead of capping at +6 total would instead add up to +13
This would mean while each type would have a 'Max' each of these could be combined for a total beyond the current max.
This would make monster UVs more valuable and would help out those sets with monster perks
Armor + weapons + sprite= total
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You idea is interesting but it would make Fiend and Undead UVs the most valuable since the weapons that deal effective damage to each aren't resisted by the other.