Spoilers
Grant could be added in season 2, as a beast in the castle at first, and then changing human, could get a backstory of being a former pirate outcast turned treasure hunter. Ellis really is closed minded if he completely writes off Grant from the second season. and this animated series would be incomplete and wasted without one of the most memorable and UNIQUE characters from the entire Castlevania series.
that aside, what's really unnecessary is cutting Sypha's hair. in the source material, Sypha has really long hair (even her sprite in SOTN). well in CVIII, she had the hood on full time until the cutscene after the castle falls, but still, it's dumb the Speakers hide Sypha's sex by cutting her hair short, when that time and place has some guys with really long hair too. Why don't they give her a face mask while they're at it then? Ellis really dropped the ball on Sypha's hair design. inexcusable. that's even worse than what the Golden Axe Beast Rider devs did to Tyris Flare's hair. Like it's so dumb. even as a golden axe prequel, you don't mess with a legendary character's hair length. and Castlevania III animated series has no excuse, its based on CVIII time period, should it shouldn't mess Sypha's hair.
Like, Ellis didn't even bother to beat Sypha route Castlevania III, didn't even bother to watch the Sypha ending on youtube. Sypha has long hair in the canon, the animated series totally messed up that fact. Like her hair in the tv series is even shorter than Trevor's, that's so degrading and not Sypha enough.
now only Alucard gets the full glory of long hair because of fanatical SOTN design influence, but Sypha is only half the woman she was. some say her more potent magic powers in this tv series makes up for it. but she could have had both beautiful long hair AND awesome ice/fire magic. (and didn't she use lightning at all? didn't notice).
as for the 4 episodes as a whole, it's decent world building. that's really neat how Trevor organizes the villagers to chip in to fight back the horde. its cool it shows the evil side of humanity, but season 2 should focus on fighting beasties on the way and inside the castle as well. it should be as more consistently action packed like the cyclops, the beasties, and Alucard duel.
Enough with the small talk and "the floor is breaking!" gravity drops. season 1 already set the stage, now Season 2 should be consistently action packed, progressive and intense like a true Castlevania. just have them travel and fight their way through the hordes into and up the castle. they have 4 more episodes to complete the CVIII, so don't mess it up with uneventful melodrama.