They are specialised in Arcane, so a standard game sequence would be : bubble-up, run, grab mobs, and then Arcane Explosion until everything is dead.
Mage has a bubble like Pal?

You can stack 4 living bombs on one target?

So Mage should be fire or arcane?

I have 5 mages now and should have 6 at some point, doing arcane but if Living Bomb is like Warlock SoC then it seems nicer to go fire.