Draining Mist

You surround yourself with a sinister red mist that drains
the life from your foes and feeds it to you. Each target
takes 4d8 necrotic damage unless it succeeds on a
Constitution save. You gain temporary hit points equal to
5 times the number of targets that take damage from this
spell (maximum 25 temporary hit points).
At Higher Levels. When you cast this spell using a spell
slot of 5th level or higher, the damage increases by 1d8
and the temporary hit points increase by 1 per target for
each slot above 4th.