I never even realized that it was possible to grind there as a kid so I always left DI on level 1. No wonder I had a hard time with Darkside. On my 1.5 proud run I grinded to lvl 10 with the Shadows, the day time battles got boring pretty fast. Annoyingly enough I never beat Riku. I think I was on lvl 4-5 or something when I tried to beat him but no luck. Well, I did leave out the shield and picked the staff so that might have affected a little. I'm pretty sure I got close to beating him, but Sora's damage output was so patchetic that I would always end up losing before I could beat him.