Black Coffin

You pull the life draining dark essence of the plane of shadow to entomb one creature you see within range. The target must attempt a Dexterity saving throw. On a failed save the target is entombed within the shadowy construct taking 2d12 necrotic damage and is trapped within the coffin until the end of your next turn, unable to interact with the outside world in any conventional way. Consequently the target is considered to be within total cover for the duration of the spell. On a successful Dexterity saving throw the target escapes before the coffin is fully formed and is unaffected.

If this spell is cast at a higher level the damage increases by 1d12 per spell level. Additionally the duration the target is entombed within is extended by one round per spell level, however damage is dealt only upon the initial casting and not on subsequent rounds.