Void Nightmare

You clasp your hands together. You pick a target and thrust out one hand at them. Silver and black energy is blasted at them. All of a sudden they see their worst nightmare form in front of them. All around whispers from the Void are heard, by the target, and deal 1d4 psychic for every person on your team each round. The nightmare can harm and interact with them and you but can be seen or heard by no one else. The nightmare can harm the target but the target can't harm it. The nightmare also can speak to the target telepathically. The nightmare deals 4d6 necrotic until dead, and 5d8 psychic. The nightmare also has a base attack of 3d8+3. All modifiers are +5.