Just like the Vanish-Doom bug, Vanish overrides certain checks. Vanish status overrides the check on such spells as Raise and Arise that forces those particular techniques to only affect dead targets, so combos such as Vanish/Arise, and Vanish/Phoenix. Vanish/Crypt Dust also works, making it a 100% Zombie inflicting enemy ability. But Phoenix Down will miss the invisible target.
When these combos are used, they'll restore a portion of their HP to the invisible target. The target will lose the Vanish status after the spell hits. Vanish/Raise restore 1/8th of the target's max HP, Vanish/Arise will fully restore a character's HP, and Vanish/Phoenix will restore 1/4 of the target's max HP.