Devil May Cry 3: Dante's Awakening Cheats

Complete the game with Legendary Dark Knight, lady will wear a new outfit while fighting alongside during the credits screen.

In the 3rd mission there is a jukebox in the bar. If you slash it with your sword you'll hear a remixed version of "Public Enemy" (a song from the original DMC) for a short period of time.

Kill 100 enemies during the credits to get a different ending screen.