Forget trying to do it in the hoard SQ as it doesn't get recognised there, just stick to the cache. You'll need a low level toon like Desert Warrior (100% inflicts permadeath) with Green Talismans, ideally mystical to make sure there is little damage applied but gives a health boost. You may also need a low level toon to steal/remove the immunity first like an Assassin Undead Axis Gunner (100% steal beneficial effects). If thats not enough an Eddie that can heal and generate power like Soldier Eddie's roulette to help keep your team alive should assist too. Hope this helps.