Solomon Muto first appeared in the original series of Yu-Gi-Oh! He owns a game shop and he's the grandfather of Yugi Muto. Solomon Muto is the one who gave the Millennium Necklace to Yugi Muto. He also made several appearances in Yu-Gi-Oh! GX.
I opened up the game and i heard his voice saying "yu-gi-oh duel links". In the announcement it says "want new cards?. You're gonna have to beat me". In the anime he had a shop that he sold duel monsters cards soo i'm betting my nickel the next character is solomon muto