Blood Transfusion

Through the power of Hemomancy you can transfer your blood with that of an ally, healing their wounds while taking your life away. When casting this spell you take 1d8 pure damage, and one creature that you touch regains a number of hit points equal to the damage you took.

The amount of damage you can do to yourself with this spell goes up by 1d8 at 5th level (2d8), 11th level (3d8), and 17th level (4d8). Note that unlike other spells you can choose to cast this spell as if you were a lower level, so you could choose to only take 1d8 damage even if you were 11th level for example.