Bojo's Consume Life

You touch a creature, and attempt to consume its life energy. The target takes 3 (1d6) necrotic damage plus your spellcasting ability modifier. If this reduces the target to 0 hit points, it dies, and you gain the following:

• You regain hit points equal to half of the creature's hit dice times its constitution modifier.
• You gain temporary hit points equal to the damage dealt. 
• Your next attack deals additional damage equal to the target’s strength modifier.

If the target was killed and was also a spellcaster, this spell does not expend a spell slot. 

 At Higher Levels: This spell deals 1d6 extra damage for every spell level above 3rd (2d6 at 4th level, 3d6 at 5th level).