Blood Whisper

The caster willingly givess up blood from their body (which the spell consumes) The target heals for 1d12 + your spellcasting ability modifier, the caster makes a constitution saving throw (DC 10 + Spell Level) or they take necrotic damage equal to the amount the the target healed for, the caster fails the saving throw if they cast this on themselves.

If a creature who is rolling death saving throws gets healed by this spell, they automatically heal for the maximum amount for the spells level of casting, however the caster automatically fails the saving throw.

If the damage from this spell reduces the casters Hp to 0 or less they gain one point of exhaustion and fall unconscious however they are stable and do not immediately start making death saving throws.

An Arcane Focus can't be used as a substitute for the material cost of this spell, so long as the caster has 2 ounces of blood in their body they can cast it.

The spells healing increase by 1d12 per level of the spells casting above first level, and can heal Living and Undead targets who aren't deaf but not Constructs.