Chill Touch

Make a ranged spell Attack against the creature.
On a hit, the target takes 1d8 necrotic damage,and
it can't regain Hit Points until the start of your
next turn.
If you hit an Undead target, it also has
disadvantage on Attack rolls against you until
the end of your next turn.
This spell's damage increases by 1d8 when you
reach 5th level 11th level and 17th level