Blood Mephit

When the mephit dies, it explodes in a burst of blood. Each creature within 5 feet of it must make a DC 12 Dexterity saving throw, taking 7 (2d6) poison damage on a failed save, or half as much damage on a successful one. A hemomancer that would take damage can use its reaction to instead regain hit points equal to the damage it would have taken.

While the mephit remains motionless, it is indistinguishable from an ordinary puddle of blood.

The mephit can be used as a willing creature for sacrificing hit points to power actions of hemomancy.

A target creature within 5 feet of the mephit that is not a construct, elemental, or undead must make a DC 12 Constitution saving throw. A creature wearing heavy armor makes the save with advantage. On a failed save, the mephit absorbs itself into the creature's bloodstream and remains there. The creature is poisoned and takes 7 (2d6) poison damage at the end of each of its turns. A creature can use an action to repeat the save, ending the effect on a success. A creature that is immune to poison is immune to this action. The mephit can't be targeted by any attack, spell, or other effect, but if a host creature takes radiant damage, the mephit also takes that damage. A Medium-sized creature can have 2 donating mehphits at one time, and using an action to succeed the saving throw will expel both. For each creature size above Medium, the amount of donating mephits possible doubles.