I've been dying to recreate my PBAoE nuker ever since I deleted him just after the AoE nerf. I definitely think it's possible, just needs to be very precise. The main point is you have to get all the damage to hit at the same time, or the AI will scatter after the second AoE hit. So, we accomplish this by stacking effect times and using a knockdown to hold them where they can't run away. Earth and fire is definitely the way to go so you get damage and defense. I have a build worked out somewhere, but can't find the card right now. But basically, it's high earth, fire, and enregy storage with skills picked for fast cast times, and damage per energy cost. After concidering a bunch of knockdowns, I went with meteor shower. Yes, it's costly, but the key is that it doesn't hit untill 3 seconds after you finish casting it... thus allowing you to cast other stuff that will hit at the same time. So, skills, in order:
fire attunement - cast before fight, and let energy regen to max
Kinetic Armor - right before you go into the fight
meteor shower
bed of coals
double dragon
aftershock
crystal wave/Tenai's Crystals
inferno
Haven't gotten to try it yet, but in theory, this would be a solo farming build too. Just barely enough survivability, but you only have to make it a few seconds, and they're all dead. The way it plays out is you finish meteor shower and the aftercast and cast bed of coals. The AoE AI won't trigger until the second hit of bed of coals, which will come just barely before the meteor shower KD. So, after meteor shower and aftercast, bed of coals and aftercast, you will be in the process of casting double dragon as the KD hits, making the end of it's aftercast just in time to hit aftershock while they're still knocked down. As they stand up, they'll freak and try to run, but you get crystal wave off before they've gotten far. Now, I doubt you can get inferno off too, unless you wait for them to settle and return... not good. So perhaps add armor of earth (since you aren't concerned with running anyway - you want them near you) or aura of restoration.
Haven't gotten far enough to try it yet, but my previous use of AoE nuking says it should work.... if anyone wants to try it out, let me know how it goes
Edit: or maybe trade flame burst for inferno, for the extra range of "nearby" instead of "adjacent"