This page in French says the game was delayed.
http://castlevania.retrogaming.fr/pu...drive-genesis/
According to that yellow blurb, it seems all three were supposed to be released in 1993. What really happened though:
Akumajo Dracula (X6800) - July 1993
Akumajo Dracula X (PCE) - October 1993
Vampire Killer (MD) - March 1994
So, this album coming out early November 1993 makes sense with a delayed Japanese release of Vampire Killer. The album was certainly meant to be released after all three games were on sale.
All three games were also developed at the same time, maybe the X68000 episode started a bit earlier, can't find a solid reference to this.
Check out the translated interviews:
http://shmuplations.com/akumajox68000/
http://shmuplations.com/chinorondo/
This interview confirms the three games were developed at the same time... but the link is gone...
http://gosokkyu.com/post/79456686343...interview-lead
Someone from the Castlevania Dungeon who translates articles from Japanese said this to me
"The MD and PCE games were definitely developed by the Tokyo branch (the NES games, as well as the MSX and AC versions were developed in Kobe). According to the director of the SFC/SNES game there were at least two different units in Tokyo. The one he worked at was responisble for the SFC and MD version. Rondo came from a different unit. Most likely the X68000 game was developed there as well since some of the staff gets a special thanks in the credits of Rondo. Also, comparing staff credits I concluded the Dracula Densetsu games and Kid Dracula were mostly likely developed there as well, but I disgress."
Aaand to finish this monologue, I have seen the following:
the pce game demo disc that ends with the text "coming autumn 1993" --> game released october, check~
the x68000 game demo floppy that ends with the text "coming summer 1993" --> game released july, check~
need more digging to find out if a 1993 release date for vampire killer was printed in a magazine ad or article
pretty sure there must be more info in some mid-1993 megadrive fan magazines