Forgive the bad recording. My PC is very bad.
This is my frostbolt ice nova hierophant, and the best build I have ever played. I spent about 17ex on the entire build (very likely less). It has room for upgrades, but at the moment is sitting at 4M dps per ice nova. The damage is strange to calculate because you can cast 2 Ice nova from frostbolt, and they usually overlap which is 2x the displayed damage. It perma-freezes anything that can be frozen and has enough dps for all content. Very tanky with 4k+ life, 2k ES, 50% MoM, Lv 20 vitality aura, and both life and ES leech.

PoB: https://pastebin.com/yAfYCb1B