@zyyiszyy: I'm sorry I do not support garena client, can handle onlythe standalone one for international servers. Even the Steam client is suported due contributors' effors who provide the deltas for offsets.
@EvilMadeFlesh: I haven't met a rare devourer in the last days so cannot confirm (and thus fix). I ran necropolis a few times, the wall-climbing spiders always had their icons for me.
@Jesper6: I wouldn't do it at the moment. Someone could create a hud plugin with unique mobs health... something like this https://i.imgur.com/2AY546m.jpg in wow