if you swap bosses during their death animations it counts as if you killed the one you spawned so you can kill any boss just by killing first one and spawning a harder one
D12 can beat them,but if you leave them as D12 you will have to wait everytime a water or fire elemental comes up.at least until you get to high enough multiplier that you can have some d12 and some d20 to be able to beat both pairs,but it still feels bad having to not upgrade it completely
