Planet Protector (星の守護, Hoshi no Shugo?, lit. Star Guardian) is a recurring ability in the series mostly associated with Aerith Gainsborough from Final Fantasy VII. It typically protects against damage or provides invincibility.
Dissidia012 Planet Protector is Aerith's Ground HP ability. It shields both the player and Aerith from damage and flinching for five seconds. Planet Protector will also protect against HP damage, but the opponent's Bravery still drops to 0. It also cancels Chase Sequences if the player is attacked while being protected, though the player will not suffer any damage. As she is an Assist-only character, this means that the ability is used when Assist and HP attack buttons are used together on the ground, but it is a purely defensive move.
TCG The card depicting Aerith in the promotional art also comes with the Planet Protector ability.