PoE Crest of Desire builds without Herald of Thunder, Tornado of Elemental Turbulence

This build revolves around running around with reverse knockback cyclone, blowing things up with Molten Shell, triggered with reflected damage from Hiltless and Defy Pain. Transcendence is necessary, because otherwise, a pathetic ~7k phy hit from defy pain would only tickle the molten shell. In PoB, this build is near-immortal with enough damage for end-game content. Super fast boss kill speed when you can get Vaal molten shell up. The only thing strong enough to kill it, is itself (or any other large phy hit while molten shell is down.) But I have some concern

tldr: molten shell go boom for \~2M dps, generally invincible, and maximum jank I discovered an interesting interaction with Power of Purpose (PoP) awhile back, namely that any "Gain maximum mana as extra maximum energy shield" modifiers actually use the pre-conversion maximum mana (verified in game). This means mana stacking gives us both armour and energy shield. However, I couldn't figure out how to get reasonable damage out of the build... until this patch! The core of the build is to stack mana to get over 50k armour, to make maximum use of Molten Shell. Molten shell gets popped by atta