How isn't he? 3rd wave tuf champ, currently tied for most fights in promotional history, more fights and wins at MW in ufc than any other man, 2nd most time spent inside the octagon at just over 6 hours, currently tied for most wins in promotional history, leader in significant strikes landed in ufc history, and MW champion. Takes care of the legend portion.
And he very much is amongst the first wave of British stars to come in and be succesful in the UFC when people used to shit on brit mma for having bad wrestling, and has been carrying that banner ever since helping UK MMA get to where it is today. Before him it was basically only Ian Freeman and Ian just didn't have the kind of impact that bisping did. Without his influence in making UFC a thing in the UK we may not have some of the great fighters we do in current day. So that takes care of being a pioneer. Anything else?