https://pastebin.com/wdi0K90T

Basic premise is to soft-stack Intelligence, since it will in turn increase mana and Energy Shield, then use the % extra mana as Energy Shield, % increased spell damage per Int, and % increased spell damage per Mana, to have a large amount of synergistic damage scaling with Energy Blade + Battlemage, Archmage, and Arcane Cloak.

All this extra Lightning damage gets added to Ice Spears and converted to cold thanks to Call of the Brotherhood. Ice Spears will basically always crit thanks to Inquisitor + a few crit nodes. The skill fires several projectiles, the first one should hit, freeze the boss, and then the next 2 get a ton of extra fire damage from Heatshiver. Thanks to Inquisitor, resistances are ignored so it's not an issue that half of the damage is fire.

Will this work well? I'm worried that there aren't enough defensive layers, not sure how useful Arcane Cloak + MoM will be for not dying. Also unsure if a 2nd Call of the Brotherhood for more Lightning -> Cold leading to more Fire thanks to Heatshiver would be worth. Also not sure if I understand damage conversion correctly, maybe Cold to Fire support is actually bad for Heatshiver.

An alternative could also be to skip Call of the Brotherhood entirely, and take Trinity Support. That would allow for maybe capping resistances thanks to a purely defensive ring/getting more life/armor/ES.