The Special Edition of Devil May Cry 3 was released January 24, 2006 and came with a wide variety of improvements on the game. It was released for $19.99 as part of the PlayStation 2 Greatest Hits collection. It offered an additional playable character, a new game mode, new boss fights and an adjusted difficulty scale. Most of these changes were popular requests after the release of the original version of the game in 2005.
The most notable addition was that Dante's twin brother Vergil was a playable character through the entire game. A new survival style game mode was added called the Bloody Palace which had 9999 levels, allowing players to test their skills and see how far they could go. The Jester was added as an early boss with optional battles against him available later.
Finally, the difficulty of the game was adjusted so that the difficulty scale was more in line with that of the Japanese release of the game. The normal difficulty has become easier so your first time through won't be as punishing but additional difficulty modes were added on the other end so that no difficulty was lost. It should be kept in mind that these difficulties weren't necessarily any harder than the original version of the game but were added to preserve what already existed.