This is a really sick fan battle! I love the creativity of the different copy ability attacks, they're all really fun to dodge.
Also, the replicated battle system is super solid, so good job on that (would be interested in knowing what engine you used, btw)
I think this mod would definitely benefit a lot from having the slowdown-soul feature, especially for the trickier to dodge attacks. (if you don't know, in deltarune you can hold down X to move the soul at 50% speed. I only found out that feature really recently lmao). It also feels a bit like diagonal movement is faster than moving on just one axis, so if you haven't normalised the movement velocity it might be worth doing so to get a smoother movement feel.
Overall though, I really like this fangame. Looking forward to see what else you make dude.