It is the help for IMO the hardest trophy in the game - Fighting in Style. You can also get a variety of other trophies as well, but you have to work a bit for them. For example, hardest Survival courses are cleared, and you need to do the ones from Hard to Rookie.
I am confused, is this to help for the very hard trophies like ''Unlock all costumes''?
Or you can just worry about completing Survival from Rookie to Normal only if you choose my save file instead to be assign to you, instead of Split's save file. Just download my save file and ask Split if he can help you out assign my save to your profile/save... Instead of the one he's using. Maybe he will have a heart to help you out... Since I didn't charge or asked for nothing in the end, for my save file donation download. It's all about the respect and extending your hearts to me a bit for helping out as well in a way.