I think the best way to incorporate a self-heal is just to make Delirium heal a large percentage of Health while Grit is up instead of recovering MP.

If you're pulling, Blood Price + Quietus will keep your MP pretty high especially while doing the Soul Eater combo. Then you always have Carve and Spit to fall back on.

With an 80 second cooldown, I feel like it wouldn't be too gamebreaking and would compete with WAR's Equilibrium heal.