After finally killing Elegon with 8 healers (we have so many healers we rotate them being DPS when we don't have enough DPS, seriously what is wrong with our guild) we're on Will of the Emperor. My Enhancement set sucks and I suck at the spec (I do like 30k in heroics) that I'm better off as Elemental but the spec is not so hot for the fight.
Any tips for how to be the most useful to the raid?
glyph flame shock, dot both biggies and kill other mobs when they're around, always flame shocking different targets when cd is up. this will grant you some nice instant lava bursts also take ancestral guidance so you can use it everytime the aoe effect on the floor starts. this will help healers immensely. take earthgrab totem too to keep some cc around and that's what i can remember for now
accept that your dps will be sup-par. The only way you can do 'good' dps on this is to tunnel one of the bosses and do the dance correctly. If you are required on adds (sounds like it). You will get most benefit out of ascending the bigger adds and pulling it away from the heal stack on the 3rd spawn or so of them, this will 'catch-up' the raid dps on the add race and give everyone else breathing room when titan gas spawns.