Phantom Force causes the user to "vanish" on the turn it is used, making it semi-invulnerable, and then reappear the next turn causing damage.
Phantom Force hits the target even if it is protected by a protection move, and removes the effects of protection moves from the target for the remainder of the turn; if it hits a target that is protected by protection move that affects its whole side of the field, it removes the protection move from that entire side of the field (even if the protection move would not affect Phantom Force, such as Crafty Shield). If Phantom Force hits a Pokémon protected by a move with a negative effect (such as Spiky Shield), the user will not suffer the negative effect of the protection move. Phantom Force cannot remove the effects of protecting moves if it does not affect the target (such as if the target is Normal-type).
You'll get the Phantom Force status condition, which lets you charge power to try a powerful attack on the next turn. It breaks through the enemy's Protect, Wide Guard, or Quick Guard to damage the enemy.
In the anime
Appearing from a portal
The user vanishes somewhere, then strikes the target on the next turn.