After the somewhat disappointing news of a lack of online co-op in Hyrule Warriors, we do now at least have some interesting details on how the online functionality works in Adventure Mode.
The latest issue of Game Informer includes an interview with Producer Yosuke Hayashi. “The Adventure Mode features a ‘Network Link’ feature.” he explains. “This allows you to add a ‘Link’ to your maps whose level is based on other users’ play data. If you come to this Link’s aid and fight alongside him, you’ll get access to special bonuses.”
It sounds like you will receive an AI-controlled Link based on someone else’s data, as well as some potential rewards — similar to how SpotPass is used in a number of 3DS games. While you may not be able to play with a real person online, at least you can still exchange data in some form. The promise of “special bonuses” sounds like it may prevent the idea from being a pointless gimmick, too.