Buff kulemaks grip, add one more modifier to it, maybe something not random.

Kulemaks invitation is the cheapest most worthless boss key in the game currently, even cheaper than 150 breach splinters, why? obviously the loot is terrible.
Kulemaks grip which is the main attraction is always lackluster, even if you have all perfect mods for your build a perfect breach rings can be better or just slightly worst, while not being restricted to a huge RNG wall.

I suggest you add (for free, on top of all the mods it can already have) something like 8% increased energy shield or hp, or both, or even +-8% increased es, life and mana (yes, all 3), so every build can synergize with it.