I'm doing it for Rihanna- Soulja Boy slams Chris Brown ,takes jibes at 50 Cent and Mike Tyson

 It is no news that Soulja Boy and Chbis Brown are taking their beef to the bxing ring in a fight promoted by Floyd Mayweather and 50 Cent.While Floyd is training Soulja Boy, Mike Tyson has stepped in to train Chris Brown.
Souljaboy took to twitter a few minutes ago to slam Chris Brown ,vowing to defeat him and saying he is doing it for Rihanna.He also mocked Mike Tyson and 50 Cent who are on Chris Brown's side..