Baleful Blink

You curse one creature to the edge of the Ethereal Plane. The target begins to shift rapidly between Ethereal Plane and the plane you are currently on, withering their life force slowly. 

Targets that fail their saving throw against this spell:

• Gain the Spiteful Omen condition.
• Break concentration.
• Have disadvantages on all attacks, and concentration saving throws. Creatures casting a spell on themselves, do not impose initial disadvantage.
• At the end of their turn, the target makes a Constitution Saving Throw. If they succeed the spell ends, if they fail, they remake the save at the end of each their turns for the duration of the spell.
• Can still move around but are unable to use Baleful Blink to move through walls, solid objects or the Ethereal Plane because the target shifts between the two planes so quickly.

Spiteful Omen: Take 1d4 Necrotic damage at end of every turn, gain disadvantage on saving throws against Psychic damage. Psychic attacks against this creature also have advantage. All other attacks against this creature are made with disadvantage.