When it comes to rematches in mixed martial arts, there seems to be little room for mediocrity whether we’re talking about the expectation or the result. If the first fight captured our imaginations, then we as human beings tend to let expectations run wild when going into the second meeting. But as far as results go, MMA sequels seem to either continue to pile on the action atop the intrigue of the horror a la “Aliens,” or they just end up leaving us with that feeling we had when we walked out of “The Matrix Reloaded.” That said, this sport has given us plenty of “Godfather 2” candidates over the years that are worth acknowledging.