Blood-Aid

Your spell bolsters your allies with toughness and resolve through a Blood Ritual.. Each target's hit point maximum and current hit points increase by 5 for the duration. 

The three creatures must offer 1 Hit Point of blood to the cloth, either before or during the Ritual to gain the benefits of this spell.

Special: Target any number of creatures who participate in the ritual. Each target's hit point maximum and current hit points increase by 5 for the duration and gain temporary hit points equal to the your spell-casting modifier. You take 5 necrotic damage for each target of the spell, and your hit point maximum is reduced by the damage taken.

This reduction lasts until you finish a long or short rest, or until all temporary hit points created by this spell are lost.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, a target's hit points and the necrotic damage you take for each target increase by an additional 5 for each level.