Master Round (VI)

 is an unused passive item that was likely a final Master Round for flawlessly beating the Lich.

Effects

 * Grants an extra heart container.

Trivia

 * It is possible that the reason this item was removed was due to it being useless, since killing the Lich ends the run, or because it would be too difficult to be unlocked.
 * Since "The Sixth Round remains unfired" (as per the 5th Master Round's text), it is possible that this is the bullet seen killing The Gungeon itself once the Lich is defeated.