Ok, so Nintendo should sue the group/company he was a part of and not the individual. The device was for hacking/modding. The fact that pirates used it too is incidental. Nintendo ships games in which you can’t even play 4/5 of the game due to a game breaking bug. The only way to access the rest of the game is to mod your ds to get past the bug. There’s also software preservation aspects so we don’t lose our digital history.
Honestly, fuck Nintendo. You don’t own software even if you buy it, so I’d argue that it’s not theft to use software without paying. But I digress.