Replacement Series
5-level Necromancy
You empower yourself with deathly energies, gaining the ability to harvest life from your foes. When you cast the spell, you extend a black tendril out to one creature you can see within range. The target must make a Constitution saving throw. On a failure, it takes 6d8 necrotic damage and has its speed halved until the start of your next turn. On a success, it takes half as much damage and suffers no other effects. You regain hit points equal to half the damage dealt. Until the spell ends, you can use your action on each of your turns to repeat the effect against a creature within range.
At higher levels: When you cast this spell 6th level or higher, the damage increases by 1d8 for each level above 5th.