It's one of the most impossible sounding things the game has ever asked me to do. I mean, there have frequently been high level heartless I couldn't defeat easily, and trial missions I couldn't do, but it was always just icing on the cake -- never core content that I felt like I was missing out on. I've always been able to get all the avatar parts if I wanted them, everything like that. This is the first time that I really don't think I'll be able to finish something I consider a core aspect of the game. And maybe that's my fault, for even thinking that upgrading this keyblade is important, but it's something I'd really like to do, and I legitimately cannot do it. Even if I wasn't currently out of town and was somehow able to play all day, I'm still not sure that I'd be able to get those extra 72 drops.
I'm going to go ahead and upgrade mine to +29, but I guess that's all I can do. And I'm really bummed about it.