Hey you guys, I just did some research and may have found something. You (theoretically) might be able to unban yourself with
ONE 3DS!!! This is my idea...
1. Backup your NAND and SD (you'll see later on...)
2. On the 3ds, download TinyFormat
3. Click on it, wait for it to nuke your NAND
Please Note: Now that you have reset your 3ds, you should now have a new movable.sed file (and thus a new friendcode file)
4. (Assuming you have A9LH) Go into Decrypt9, and dump the friendcode file
5. Restore SD backup
6. Restore NAND backup
7. Check to see if everything is the way you left it
8. Follow the tutorial as you wish...
Please Note: This is
ONLY A THEORY! I have heard of people unbanning themselves by formatting, and this is immediately what I thought of. I cannot test it myself because my 3ds isn't banned, even though it should (theoretically) work. Plus, if you backup (like I said) then you have nothing to lose. Anyways, happy gaming!
Another thing: If this actually does work, that would solve a lot of issues... That would be super wicked...
You guys may also want to go on here, I found some great info:
https://gbatemp.net/threads/pokemon-3ds-ban-what-you-need-to-do.449472/