During a fight with Vergil, the Red Queen shatters under the strength of Yamato and Vergil's speed. Vergil grabs the devil bringer and absorbs his power. Nero's arm returns to normal and passes out. Dante picks up Nero and takes him back to the shop. After he comes to, Dante explains what happened. He swings open a door and reveals a devil arm that personally belongs to Nero. What is it? How's it work?