Mikaboshi, also known as the Chaos King is a very powerful opponent. He has taken on power hitters like Thor and Hercules with ease. His power knows no limits, but the Beyonder is no stranger to great power either. Both of these beings have incredible long range abilities and can fight from up close as well. What ultimately gives the Beyonder the edge here is his speed and flight. Mikaboshi has these abilities as well, but I do not believe that they make him a match for the Beyonder. Beyonder wins.