Topic: Nintendo Network ID Help?

Hi, I really have no idea what to do and don't want to format my 3ds system because i will lose all of my E shop things that i've bought so if someone knows how I can fix this problem that would be great thankyou:

ok, So I made a nintendo network ID on my new 3dsXL, I made a mii for it and bought things in the E shop. Then I thought I could link this ID to my brothers new Wii U . This is where everything whent wrong. Linking the ID deleted my Mii and user information from my 3DS and added my brothers information.
I've looked everywhere for a way to simply get my mii and user information back on my 3DS WITHOUT it forcing the same thing on the Wii U but the only solution I've found is to format one of the systems and I can't do that because I don't want to lose all of my game save data. so, any suggestions?

P.S. if i've explained it badly then sorry :/

I dont think formatting on the 3DS would delete save data. The data is saved on the cartidges. Also if your talking about games that you downloaded you should be able to re-download the games if your signed into your Nintendo ID. You might lose the save data for the downloaded games.

You'll just have to make a second Mii like your old one.

That's good, at least I wont lose my games save. But what about the update for pokemon Y i downloaded? The main reason for formatting it is to remove the network ID so I can create another one separate to the Wii U. Will doing this affect the update or game, or can I simply download it again?

i can't, this is what i'm trying to get around If I make another Mii for myself on my 3ds then it forces that Mii and name onto the Wii U.