I just found some postings that claim that you can line-of-sight Loken's AoE attack. This means we might be able to tank him next to his chair and switching to the left/right side after each AoE. I'm gonna try this soon
I used to just strafe left/right away from him in normal mode, but due to higher damage and bigger AoE range, this doesn't work for me anymore in heroic mode.