This is a hack which makes Solieyu Belmont playable in Castlevania II: Belmont’s Revenge for Game Boy and Game Boy Color. Solieyu is the son of CVII:BR’s main character (Christopher Belmont) and is encountered as a near-final boss in the original game. He can move and jump faster than Christopher did in the original game. The sprite has also been touched up.
There are two patches. One for the US version of CVII:BR for the original Game Boy and one for the Game Boy Color EU version of Konami GB Collection Vol.3 which is a compilation that has CVII:BR as an included game.
ROM / ISO Information:
File: Castlevania II - Belmont's Revenge (USA, Europe).gb