Curse of the Lich

you channel dark necromantic power bestowed from the liches tooth/finger putting a curse on your target the creature must succeed on a Charisma,wisdom or Intelligence saving throw (its choice) against your spell save DC or become cursed for 1 minute. If the creature is a celestial it has disadvantage on the saving throw. while cursed the creature has disadvantage on all saving throws from any spell cast by any spellcaster and its AC has a -2 debuff when targeted by your spells that require an attack roll from you. On the start on each of the creatures turns it must make a DC 20 Constitution saving throw or take 5d8 Necrotic damage if it is a celestial it takes an additional 4d8 necrotic damage and you regain half of the full damage dealt. 

When you cast this spell you can only use cantrips next turn

This spell has no effect on undead or constructs

At higher levels: if you cast this as a 9th lvl spell you can target one additional creature with the curse. And its range is increased to 60feet