Do remember it isnt named Vampire Killer, but Combat Cross. much like There was the Whip of Alchemy, and then vampire killer.
Or the Hunter's Whip Graves uses, or Even the Holy Whip used by Julius' Belmont's apprentice in the DoS novel sequel. (would kill for a translation of that)
We have yet to see Rinaldo, but have been told that he is still around, in the guise of an old beggar. Some of the order have even seen him. its entirely possible for him to encounter the new hero and create or present to him a new whip, one which would later become known as Vampire killer, presumably for killing Gabriel. Either that or be tailor made specifically FOR killing Gabriel and or any vampires.
Now guys saying shit about MS.
Do remember Cox said he doesnt want to be the new "castlevania guy" like IGA was. Meaning if we get any more games from them, Im not expecting THAT many. at least not as many as IGA. I will say as a liberal estimate, 3-4 more, tops.