PoE Herald of Thunder, Spell, Bossing builds

I quickly got bored of all the builds I played this league so I decided to return to my roots and make an Arc Archmage Elementalist. Well, Pledge of Hands felt like shit to me, so over the past few days, the build evolved into a Dodgy Arcssassin, stacking power+frenzy charges. I've spent \~20ex on the build so far, but you can get decent results with 12-15ex as well. There is still a lot of room for improvements, but I thought the build is in a state where it is worth sharing. I was planning to switch to Farrul's Fur, but I think

Important notes Mana regen % anywhere you can get it from is really really good - start with clarity and replace it with herald of thunder once you get enough mana regen Gloves w/ spell damage leeched as ES are a huge survivability boost. Surgeons prefix on flasks is stupidly OP (we have 100% crit chance and fast cast speed so this is insanely good for us and gives the flasks massive uptime on bossfights)