Ya, We've Got Time...

Easy Solo at Level 120+ and Beyond...

1. Normal 10-Man Difficulty.

2. Begin Encounter and kill stuff until the furnace has been bombed and the Elementalist phase begins.

3. Four Primal Elementalists have spawned.

4. Reduce EACH elementalist to about 20% health, using your weakest attack. (If you are too powerful and one shotting these, try putting on a lower level weapon)

5. Once they all have around 20% health, kill all four within 10 seconds.

6. Kill Boss.

7. ?

8. Profit. Achievement Completed.

We managed to do this today on Normal mode, 07/02-2015.

The Primal Elementalists spawn in Phase 2 of the fight, as you know from Boss tactics you have to kill a Slag Elemental on top of them in order to dmg them.

The way we did this achievement was by going from one Elementalist to another, getting it down to ~15%. The problem here is that they will still get the Reactive Earth Shield (heal after 8 sec). We planted a dispeller inbetween two of them, just keeping an eye out for dispelling. The Firecallers can also heal the elementalists so deal with these asap.

Once all four are on ~15% and you have a dispeller handling 2 each, then you want to get a Slag Elemental on top of each one. Before pull we split our raid DPS into 4 groups, assigned to each elementalist. We killed the Slag Elementals somewhat-simultaneously and then once the Damage Shield had disappated, on all four Elementalists, we did a 3.2.1 go. You have more than enough time to get the remaining % of the Elementalists done, so make sure you wait until all Slag Elementals have blown until you start DPS.

TL:DR - Split Raid DPS into 4 groups for each elementalist > Go around as a group and bring Elementalists to ~15% one at a time > assign 1 dispeller per 2 Elementalists for the 'Reactive Earth Shield' > kill Firecallers asap, interrupt Cauterize Wounds > Bring 1 Slag Elemental on each of the Elementalists > Wait for all damage shields to disappate before you go ham.

The criteria for this achievement may seem a bit misleading. Despite saying that you need to kill the elementalists within 10 seconds of each other, you do not have 10 seconds between each kill. Instead, you have a single10 second window after killing the first one to kill the other three.