The skills I use are Meteor Channel and Ice Lance. I start out straight up nuking and then when I have enough energy, Ice Lance if mobs are close, otherwise Meteor Channel and kite.
Its all about kiting, and dashing through the group with Ice Lance to get to the other side to kite. If you run too far back the mobs will race back to their spawn point. On the plus side, you can use this to split a pull if you time it right or Ice Lance run close to a returning mob and then shoot it.
The most important stat on equipment I’ve found is Wizardry. I am currently doing item runs so the other stat is Relic Hunt for Item find. It can be slow going, but Meteor Channel rules all.
Finally, make use of previously cleared rooms to duck into when the fight gets tough as you regen health after 5-ish seconds of idle time. Go back into the fight healed and burn them a little more!