Jaden Yuki (Judai Yuki in JP) is the main protagonist in Yu-Gi-Oh! GX, the second anime in the Yu-Gi-Oh! series. While there are no images of Jaden in the game files just yet, there are certain leaks and rumors with his name available. He will most likely be an unlockable character when Duel Links decides to expand to the shows' sequels.
In the anime/manga, Judai uses elemental HERO deck. They are very focused on fusion summoning. Using Elemental HERO Neos, a level 7 normal monster and also his main signature card, it can fuse into more than 10 different fusion monsters using other elemental/hero monster cards, above are some examples of it. List of "Elemental HERO" cards
His other potential signature card is Yubel. A main antagonist in one of the show's arcs, but later became part of Jaden by fusing together, resulting in a similar relationship like Yami Yugi is to Yugi Muto. Yubel is also an archetype, having multiple supports and revolves around destroying Yubel to be able to summon other monsters.