Apocalypse Spear

You unleash a shimmering black spear made of negative energy from your hand to a creature that you can see within range. 

A creature targeted by this spell must make a Dexterity saving throw. On a failed save, the target takes 8d8 force damage and 8d8 necrotic damage and has disadvantage on attacks rolls during 1 minute. At the end of each of its turns, the target can make a Constitution saving throw. On a success, the spell ends on the target.

If the target is an extraplanar creature, it has disadvantage on the saving throws for this spell.

At Higher Levels. When you cast this spell using a spell slot of 7th level or higher, the damage increases by 1d8 force and 1d8 necrotic damage for each slot level above 6th.