Bio II can be learned by Black Mages, Red Mages, and Dark Knights. Bio II's scroll can be bought from venders in either Windurst Waters, Selbina, or Aht Urhgan Whitegate. In addition, it can also be obtained from other players via the Auction House or Bazaars.
Bio II is a Dark Magic ability that deals gradual Dark damage and weakens the afflicted target's physical attacks. The rate of damage, the duration, and the attack stat reduction are all improved over the original Bio spell. The Bio status can be cured with Erase, Esuna, Exuviation, or numerous items, but not by Poisona or Antidotes.