Captain Lnces EB Inquis Life sustain?

im wokring off of Captainlances EB guide: https://pobb.in/dNspv90glUsN
Hes using Blood magic (reserving a bunch of life)+ rathpith sacrificing 10% of his life every spell cast.
What Im trying to figure out is how is sustaining his life pool. He Takes zealots oath as well so its not regen. hes a spell caster so its not leach.
Thanks in advance

Only guessing here, have not played the build, but I think it might be eternal youth.

Damage to energy shield will not interrupt the recharge, so it would be constantly recharging. Similar to using EB.

https://www.poewiki.net/wiki/Eternal_Youth