If you can get a lot of -recharge gear you can spam Eruption. I've been messing around with different builds using custom maps and whatnot and the Conjurer seems the best non-Ternion caster build I've been able to come up with. Toss 2 or 3 Eruptions up in a group of mobs and watch them get obliterated while your CD TRIES to tank them but can't cause they die too quickly
Its quite funny actually. Of course as a Conjurer you always have access to Ternion so you can always use it until you get enough -recharge gear to be able to spam.