Never put your Living Bomb on Keleseth, but be sure to having a Living Bomb on each other bosses, even when you are fighting Keleseth. It will grant you an huge amount of HS procs.
Choose an intelligent location, you have a huge range, it can prevent you from being bumped from Shock Zones and Empowered Shock Vortexes. Also you will be able to switch target easier.
If the Flame Sphere will be deadly for you use your Fire Ward (or even Ice Block it).
Nothing special to notice in heroic mode. Do not move !
You can be selected to take care about Kinectic Bombs in Normal Mode. Use your Arcane Barrage on them right after your Arcane Missiles channelling.
If the Flame Sphere will be deadly for you use you Fire Ward.Â
If you have Incanter Absorption you can get a very nice SP buff on this boss. By absorbing some Flame Sphere damages.
Try to move as little as possible.
Nothing special to notice in heroic mode. Do not move !