Free Step Dodge

Fraid you don't have to do that to unlock anyone, don't know who told you that.

Well there are 2 characters that stay locked after you beat the story which are Kilik, and Algol. And to unlock them you have to either clear arcade mode or clear legendary souls. Algol it hard to unlock him in arcade cause chances of fighting him there are very slim. So I went with the legendary souls route.

You can also unlock them by reaching a certain player level online or beating their styles in quick battle, I believe that's how I did it.