https://screenrant.com/castlevania-netflix-season-4-exciting-things/S4 dropping in a few weeks. Confirmed to be the final season, but spinoffs are possible.
My low expectations for the previous seasons were vastly exceeded. I'll be going into S4 with higher expectations. The show has established enough opposing forces now that there is a high bar for what it could accomplish by tossing them all together.
I really like Isaac, I hope him and Alucard somehow end up "winning together". They both strike the right balance: having a detached view of the world for what it is (bad), which gives them the proper perspective to try and push for real change.
Sypha can die, either in childbirth or shortly after delivering Trevor's child. This gives Trevor something to live for (completing the arc of the aimless man we saw in his introduction) and preserving the Belmont line (which is integral to this universe).