Suggested by Sonic Gateman is far from the most impressive Megaman character around but he is still more than a match for King Dedede. This comes down to speed and versatility. Try as he might, King Dedede just won’t be able to land any real sots in. Meanwhile Gateman has some decent long range attacks coming out of his gate and can pepper Dedede with hits until he goes down. Then it will be the end of the road. Gateman wins.