Greg Hardy's Goin' Down in MMA Fight, Says His 1st Opponent

[[tmz:video id="0_651tifg5"]] Greg Hardy's first MMA opponent has a message for the former NFL star ... I'M GETTIN' THE W, SON!! FYI, Greg's first pro fight is on Nov. 4 at Rise of a Warrior 21 ... and we got the man who's gonna meet him in the cage --…