This boss battle was neat because it featured fake copies of the heroes of Castlevania III: Dracula’s Curse, besides Alucard. The heroes being Trevor Belmont, Sypha Belnades, and Grant Dynasty. Poor Grant didn’t show up later in the Netflix anime.
All three phonies fight just like their abilities in Castlevania 3.
Granted, it’s a lot of stuff going on, but it’s actually not as hard as it may appear.
I think it’s rather neat we get to see all those characters modernized as the NES game left much to the imagination of the gamer, on how these characters looked like.