The swag you’d expect.
Participating and Clearing Event Quizzes gets you special drink coasters, each based on the Main Character of each show, with a 9th Coaster unrevealed.
Solving the Mystery Solving Corner, another section, gets you a Kuriboh Token
Completing Bonds of Duelists, a round robin event, gets you special rewards in Duel Links and Master Duel by playing PVP. (These run until February 18th, so no worries about missing out)
There’s a Digital Photo Corner where you can get Tokens featuring you and your anime favorites.