Not much opportunity for him to do anything but get knocked on his rear running headfirst into Sixshot. Megatron hasn't had the Phase Sixer program explained to him, but he knew that he was bristling with weaponry and well armored. Not to mention the eons of experience he lacked.

So he lowers his stance and begins to circle around him, waiting to see how Sixshot will react in turn. The best thing might be to just play this thing by ear and see how long he can hold out.