Im not actually a huge fan of Castlevania. It's.....meh.....I dont get why a whip has legendary powers.
Because it has the soul of an innocent contained within, if you wanna get technical.
As for SotN, Alucard uses swords, maces, and various other stuff but never a whip.
With DoS, Soma Cruz uses knives, guns, swords, axes, a RPG, a lead filled Teddy Bear and other off the wall stuff.....but once again no whip.
Though both games do feature a Belmont in the post game you can play as with a whip.
I never played the first game with Soma in it, but I'm told he could wield Excalibur. Since he couldn't draw it from the stone, he swung the whole thing rock and all like a gaint club.

*EDIT*
Oh! And I have a theory that the Belmonts are really just a clan of hungry hobos.
Who else would eat a pot roast that fell out of a thousand year old castles wall?