Don't Run From Nova
Tank pulls him. Stack just like the strat above. When Loken casts nova, do not run, just eat it and continue to burn him. This is how you get the achievement. Everyone in your group needs to be able to take the damage and still have a decent amount of health left. Have a nature resist aura is very nice because it mitigates some of the nova's damage. Having a group oriented healer helps a lot with this tactic. If you have a death Knight, they can use Anti-Magic Shell to absorb one of the Novas.