How to be a less predictable M.Bison?

Hi guys.
Im new in this forum and im actually new at the fighting game community as well.
Started to play SFV with BISON , and went into a super full immersion of the basic of the games.
I used to play with 2/3 friends , and after 3 months , im start to feel that im stuck in big problem : my predictability.
This happen when i play too much with the same people for long time , but it also because my playstyle of Bison lack of mixup.
Bison has no normal overhead and his Devil Reverse is too slow to really surprise people , ok he has a lot of frametraps and everything he hits is plus on block , but if the opponent know that , and play pretty passive , i barely have the chance to break their guard.
I reach Super Gold level online , but at this level , i only win matches with people who have no idea of how to proprely play against bison , everyone else can easily kick my ass by guarding all the time and waiting the right moment to punish.

I need some advice to improve my actual level.