Now, the most extensive mapping I've ever done was for some emulators, mainly PlayStation so mapping controls to the dualshock 4 was never an issue.
So dolphin was the one time I've really mapped one controller to another. I mapped A, B, Y, and X to...well, X, Square, Triangle, and Circle respectively, L and R to the triggers, and Z to the right bumper. C stick was right stick, obvs.
In terms of in-game button mapping. Devil May Cry. Nero's Blue Rose on right trigger, DT on the D-pad.
Fixed my sentences, sounded dumb.