nice spell :thup:
i had no problems with multi instance(i added about 30 level6 mobs and removed the dragons, then started spamming away(just so i could see things getting knocked away))
only got to about 5 frames after 20 seconds of this, wasnt really counting instances of the spell:nuts...
nice spell
have to say it looks like a flame strike on roids, creating a actual mini volcano would look cooler, and shouldnt be too hard to add to add in code wise