BO

Brian Oyster (born March 27, 1990) is an American Rapper and professional fighter. He competes on the Def Jam circuit, and Street Fights. He is best known for his time in Def Jam. He is best know under the name of BO and KO. BO team up with severals fighters such as Nyne and Trick, he was with Chiang for a while. Brian is a good friend of Nyne.

Brian won several championships in his career including, Solo Championships (4 times), Free For All (4 times), and most, he is Seven-times Tag Team Champion with Nyne (4), Chiang (1) and with Rome (2). Brian become one of the most dangerous, accomplished, and successful fighter in Def Jam making him the crowd favorite to everyone.

Brian carries three dangerous fighting style (Martial Arts, StreetFighting, Kickboxing). He has powerful strikes that K.O. his opponents really quick. Brian throw fast jabs, kicks and strong haymakers. Def Jam call him the king of K.O. at that time when he K.O. his opponent fast with just a punch. BO finished his opponent in 10 seconds. The fastest KO ever! BO is in the KO Hall of Fame in the first place. His name later become KO (2006) leaving his old name BO.

Brian realease his first CD in 2004 (Pop Your Collar), his second was release in 2006 (BombTrack) and his last in 2008 (Front To Back). His albums are base on his finisher moves.

Brian main finisher move is called "Pop Your Collar".

Brian retired in 2010 as a professional fighter. He announce that in the ring before facing his last opponent C.J./Nyne in the ring. BO won the match. At the end he got respected by his old time friend C.J., before leaving C.J. and the crowd clap to BO for respect.

Brian also appears in the video game Def Jam Fight For New York as a playable character. He appears at The Foundation as a speed test challenge, in the Free For All Tournament located in the Power Plant and at last in The Heights in a One-On-One Rematch, but only this time BO is harder to take down thanks to his Toughness and Health. His finisher move is "Pop Your Collar" base on his album title.

Bo also suppose to be in Def Jam Vendetta along with his partner Nyne and other fighters but he was absent in that day. BO suppose to be there to be Nyne's partner in the Tag Team Semi-Finals, but instead they put Nyne in The Dragon House along with Cruz and Masa.