WARNING: The following contains spoilers for Castlevania, now streaming on Netflix.
The fourth and final season of Castlevania threw fans for a loop when it introduced Death as the main villain. Masquerading as the Alchemist, the ghoul tricked Saint Germain, using him to bring back Dracula and Lisa Tepes, giving it the ability to destroy Earth and collect as many souls as possible via the Infinite Corridor.
Though it's an interesting twist -- and despite both figures seemingly dying in the end -- a Castlevania spinoff with Death and Saint Germain would do their joined arc more justice than the original series ends up doing.
Saint Germain's lost love in the Infinite Corridor is so underplayed in Season 4 -- that needs rectifying ASAP. We merely get a glimpse of the woman and a hint of the reason he's been working as an alchemist, hoping to unlock the secrets of this passageway. A spinoff can focus on his time getting lost in the Corridor and pursuing her, while also bringing in other villains and monsters from the Castlevania franchise.
His story felt rushed, convoluted and forced, but this approach adds nuance to Saint Germain's story and makes him more sympathetic. To see the romance unfolding in flashbacks would make sense because we never witness them as a couple or chatting to provide context on why he'd break reality for this lady. More of their adventures would pave substance over style, and if he's able to navigate the Multiverse, we can get different Earths, personalities and endings for Trevor Belmont, Sypha and Alucard.
A spinoff can even tie directly into the Castlevania games where each one is a different Earth, which allows for more of Dracula and Lisa Tepes -- whose story ran admittedly light as well. It would intricately map Saint Germain's journey and give him ample reasons to want to betray Team Belmont, despite knowing they're heroes. His otherworldly travels would further reinforce his need to find his beloved, while having him lose faith in everything and everyone else without her.
This direction also allows Death to truly detail its mission, not just appearing like a character chucked in for the sake of ticking off that box where the creators need to insert a villain from the game. Death should be the Thanos of Castlevania after all, so we'd love to see it shapeshifting and manipulating all figures across various realms, including the vampire council.
The Corridor is Death's main tool of deception, so we could see it being used to influence Dracula from the very beginning when he was Vlad the Impaler, wrapping up the story in full and showing why all these forces were meant to collide. This erases the feel of Death being a convenient plot crutch and would flesh out why Trevor and Co. found deus ex machinas such as his family's blade in the end to challenge the enemy.
A spinoff would make up for Castlevania killing off the vampire king too early and also not using the Forgemasters properly in the final season. Moreso, it could prove Death to be the ideal puppet master -- while not realizing fate was also stringing it along and thus, a victim as well.