User blog comment:GoDai/GoDai's Translations: Chapter Translations/Summaries/@comment-4979652-20120702024500/@comment-4076672-20120703130719

Pen: In this case, it may be Wangnan is unaware the FUG has decided to use him.

They may have been looking for another chess piece and decided to turn a "pawn" into a "bishop" or "King"(limited Western chess knowledge here, try not to ream me if I get it wrong). :P I think they may even have done a hell lot of investigating his identity, just to be sure. That or Yu Han Sung already knew Wangnan's identity and decided to let a "dangerous element" pass.

(I'm making this assumption Wangnan might be unwanted by the King. However, this theory is hazy because Wangnan has a ring, issued by the King, either to him or to someone else.)

I'm basing on some flimsy historical knowledge that those Princes with limited power, are sometimes used as puppets by others. Of course, this is provided he has no abilities in the long run.