Tendril of Malice

You thrust your arm outward towards one target creature. A tendril whips out from your palm, connecting you and the creature you targeted. Make a ranged spell attack against that creature. On a hit, the creature takes 6d4 necrotic damage. You may take 2d10 Necrotic damage any number of times during the duration of the spell to deal an additional 2d4 necrotic damage whenever dealing damage with this spell (the damage will only be added after the next d20 roll is made with this spell, and can be done before the ranged spell attack is made). The hit creature repeats the saving throw at the beginning of each of its turns, ending the spell on a success, taking the damage again on a failed saving throw.