Is it possible to make onion knights gain exp?
don't know for sure but it will take either some ASM hacking, or there *may* be a byte somewhere in the ISO that can be *turned off*. The problem is there hasn't been much discovered on things like this. Same is true for the Mime.
Umm...How about the Dark Knight. Can you remove the 20 kills requirement?
Pretty much the same answer. We don't know where the data is in the ISO that needs to be changed.
I heard that Onions have an innate support support that is like "No Exp" or something.
Nope, they don't..