Act 1:
After Hillock: Buy: Frost blink / Stormblast Mine. (GBG for traps)
After hellrake buy: Swift assembly, orb of storms, frost bomb. Lesser poison (quest)
After brutus: Smoke mine/flame dash/added lightning (Swap frost blink for flame dash).

Act 2:
After chamber of sins: Herald of ice. (stop using frost bomb around now)
Spider: Ele focus (quest) summon skitterbots (buy)

Act 3:
Cures of electric
Lightning spire trap: (Ele foucs, ele prolif)