Borrowed Time

A pale green flickering flame engulfs your hand in Necrotic energy. Make a melee spell attack against a creature within your reach. On hit causes 2d6 Necrotic damage, and you regain hit points equal to half the amount of necrotic damage dealt. If the target is a creature other than undead or construct, it must succeed a DC 14 Constitution saving throw.
This spells damage increases when you reach certain levels:
- At 5th level increases to 3d6.
- At 11th level increases to 4d6.
- At 17th level increases to 6d6.