There are several optional superbosses located within 'Final Fantasy Blackmoon Prophecy II. The following details who, and where, the optional superbosses are.
Superboss List[]
Anima[]
Anima is the tenth and second to last mark that the player can track for the Hunter's Guild in New Lantz. Upon triggering the tenth mark, Anima can be found outside of the town of Neirbrook.
Neo Bahamut[]
Neo Bahamut is the eleventh and final mark that the player can track for the Hunter's Guild in New Lantz. Upon triggering the eleventh mark, Neo Bahamut can be found on Lindblum's northeast coast.
Ozma[]
Ozma resides within a dungeon deep within the Kusku Salar salt flats.
Shinryu[]
Shinryu can be encountered in the town of Rivera late into the game when the player brings the appropriate items to the village for a ritual.
The Risen[]
The Risen can be encountered in the Berona Mudflats when they open up late into the game near the town of Garamonde.