Technical Wizardry
Succeed at a cumulative total of 100 reversals (single player only)
If you do not get this after you get all your other achievements or just want to get it a lot easier you can adjust the sliders to make reversaling easier.
Go to Options -> Gameplay Options -> Gameplay Balance Options -> Game Balancing
From there you can adjust all revesals to easy making it really easy to do just use a character with high technical stat and fight either Batista or Rey Mysterio and just keep hitting RT it should unlock in no time.