karmic phoenix
These bosses are almost exclusively farmed by end game players hunting pets/nests/spider eggs. It can sometimes take an upwards of 20 minutes just to find an open world and if you're an Iron player you often get crashed after only a few kills. But more importantly, these are both bosses designed as mid game content but most mid game players are lucky to be able to utilize the content due to the lack of an available instance system to them.
tacit linden
pure steeple