One time I was running a normal and we got to Atheon. We did a nearly perfect run with one portal phase left to kill him; Atheon bugs out and only teleports 2 people into the portal. We say okay bugs happen let's do it again. 2 portal phases and the 3rd portal phase bugs out, send back only 2 people again. Third attempt we go again have him down to 25% health 4th portal phase bugs out and sends back 2 people. Group as a whole says -blam!- Atheon. 5 mins later his ass is off the ledge. Fix the exploits, sure. But ffs fix the bugs too.