His motives are unknown, unless if you take a look at the recently released Dragon Ball Xenoverse 2: All DLC Pack 6 Animated Anime Cutscenes video.
Dragon Ball Xenoverse 2 DLC Pack 6 has a brand new story titled “Infinite History” in which a mysterious new teenager named Fu appears in the Xenoverse.
Dragon Ball Xenoverse 2 DLC Pack 6 will have additional cutscenes, but these are the ones that are in an anime-style.
Dragon Ball Xenoverse 2 DLC Pack 6 (officially known as Extra Pack 2) hits the Nintendo Switch, PlayStation 4, Xbox One, and PC/Steam on Wednesday, February 28, 2018.