Infernal Horde Aether lord Bug,
was just doing infernal horde tier 8 and in the very last wave an infernal horde spawned, I staggered him right when he was supposed to disappear (a mechanic the boss has) so he stayed invisible and kept attacking me while invisible, I tp’ed out and back in, I was able to see the boss but he was all red and still untargetable.
the Aether lord boss model I encountered is the same boss we encounter at the end of the dungeon to unlock world tier 3.
as a result of that, I couldnt progress further 
, 600+ Aether gone, sadge, please fix!