Castlevania: The Bloodletting
Every game series has a number of odditites that come along over time. Some games shift and change, and certain bits that work (or don't) are added and removed as the game is developed. Sometimes this then results in a game being cancelled (see Castlevania Resurrection), while other times, such as in the case of Castlevania: The Bloodletting, the announced game becomes some other game entirely.
Early reports indicate that Bloodletting was originally conceived as a follow-up to Castlevania Dracula X: The Rondo of Blood. The heroes of the adventure would have, once again, been Richter Belmont and Maria Renard who had to something something Dracula, as this was a Castlevania game, so that's what heroes were expected to do. Along the way there would have also been a rival, another vampire hunter looking to make a name for himself (and possibly battle with Richter).
Those are the heroes shown on this page, and yet the rival (the man in red) more closely resembles Richter (since he's basically just a reskin/recolor). Richter, meanwhile, got a complete redesign, making him look drastically different (and not at all Richter-like). Apparently it was a weird time for Konami.
Regardless, as history has shown the 32X add on for the Sega Genesis was a failure -- one of many add-ons and adapters Sega released in quick succession right before putting out the Saturn, and none of them (Saturn included) caught the world on fire. With the failure of the the 32X, Konami apparently cancelled the game and shifted the team to other projects (eventually series lead, Koji Igarashi, being one of those team members). All work on Bloodletting was stopped and whatever remained of the game was repurposed or deleted.
It's worth noting that although some attribute the name The Bloodletting to fan invention, Konami did register a trademark for that name in 1995. They even advertised it at the 1995 Chicago Consumer Electronic Show (the name, anyway), before quietly cancelling it.
Legacy of The Bloodletting:
As we know, Richter would appear in a proper follow up to Rondo of Blood, the hugely successful Symphony of the Night. Some of the artwork from Bloodletting was even resued for Symphony, with Fake Trevor (of the Zombie Trio) used recolored Richter sprites. Meanwhile, it's possible some of the ideas for the Rival could have gone on to influence Rihcter (and his plot elements) in the sequel (although that's just fan speculation at this point).
Meanwhile, the Rival has gone on to star in a Castlevania game, albeit a homebrew fan game. Appropriately titled Castlevania: The Bloodletting, the game is a faithful entry in the series, one that shows a level of polish many fanbrews and hacks lack. We recommend, if you're going to grab it, get it from a trusted source -- we nabbed our copy from over at Pixel Prospector (and we are in no way affiliated with that site, nor do we have any reason to advertise it other than they have a decent copy of the game).
Of course, we'd be remiss if we didn't also mention that the Rival continues to live on at The Inverted Dungeon and her sister site, the webcomic CVRPG. On our sites we've renamed the Rival as Hanz Belmont, brother of Richter Belmont. We have his bio posted once again, but you can also check out Hanz's adventures with his brother in CVRPG's sorta-spinoff, DSWC.