NOTE: Hoshi may not be his actual name, details of the upcoming Dragon Ball Hoshi Manga and Anime are widely under speculation at the present time.
Presently unknown, though he appears to be a saiyan related to Goku.
Unknown, he appears to have basic Z Fighter powers (super speed and strength, heightened durability, energy blasts, and flight) he is presumably a Super Saiyan, it is clearly shown that he knows the Kamehameha wave.
While many well known Z-Fighters appear to be his allies (Goku, Gohan, Goten, Pan, Vegeta, Trunks, Piccolo, and Android 17) he also seems to have some allies entirely new to the franchise, including an unidentified Saiyan girl, a "Mini-Buu" which appears to be a smaller version of Majin Buu (with Majin Buu himself apparently becoming a villain again) and a member of Frieza/Cooler/King Cold's species, who is the first heroic representation of this species in the DB universe.
His primary enemies are apparently Cell, Frieza, Syn Shenron (Omega Shenron), Majin Buu and an unidentified giant Namekian.