Next healer class released should be

[Rasler_Heios]

It doesn't have to be inventory based. In FFX-2 the (Al)chemist class could use potions regardless, even if you didn't have them in your inventory. Said skills were called "Stash" skills, and were describe as such by the game's Help description, "Use a hidden item. Takes time, but no item are expended."

Yes, I am aware of this technique. The OP though sounded as s/he wanted it to come from the inventory.