I play DMC4 with default controls.
No calluses here, I can Star Rave, Lucifer Guard, and E&I Rave without many problems. If at all.
How do you do the "slide", then? Or do you do the "see-saw?"
Either way, when I do the "slide, the underside of my thumb hurts like hell afterwards and becomes all red.
I know about the "claw-grip" but it doesn't work quite as well as the slide.
I know a person who would put tape on their thumb, so that way it would slide without hurting.
Change a few names and voila new IP.
People would have just accused NT of ripping off DMC. Yes, it would have happened.
Edit:
I can't do the see-saw at all, so I've stopped trying.