Undying Aura

Upon casting all allies within 15ft and the caster gain 5 + your spell casting modifier in temporary hit points and the caster takes 1d6 necrotic damage. This spell can be cast as a ritual spell with 5 minutes and double the damage to the caster.

You can recast this ability with out expending a spell slot whenever you succeed on a concentration save as a reaction until the spell ends. (when recast the temporary hit points can only go as high as the initial amount).

casting this at level of 3 or higher will increase the hit points by 4 for every level.