get fire enough for blastwave then go arcane pick up POM for some serious bust with fireball or pyroblast depending on how you spec. Frostnova anything close and single target scorch / Fireblast rotations till they come in then blastwave frostnova should kill most people faster than AE spam. AE has been nerfed nearly into uselessness over the last year or so so try to get away from it. Arcane barrage is a nice talent as well so try to pick that up huge burst from 4 mages and it's instant so scorch barrage blast and you shouldnt need much healing

Anywho good luck