E/Me's Echo Nuking Meteor Showers, 200 damage a second on Bladed Aatxes, Good Game.
Meteor Shower does indeed cost a lot of Energy, but it is the BEST PvE spell. Good Elementalists have 80 or more Energy. Try Echo Nuking, 140 Energy, and we'll see who needs some Blood is Power.
At higher levels Firestorm is simply too weak, plus Meteor Shower knocks them down.
Glyph of Energy is a good skill but it isn't really easy to get... you have to venture up to Granite Citadel (which most people don't) and go Skill Capturing out in the Mineral Springs.
If you don't understand what Echo Nuking is, take a look here: