When you see Meta Knight, do not get the sword. Instead,take Kirby up to where Meta Knight is standing.Now,just bug him.(use your attacks,try to inhale him and stuff like that.)When he gets sick of being bothered,the sword will disappear and Meta Knight will fight you.

You don't actually have to irritate Meta Knight to fight him without the sword, all that you have to do is just wait anywhere for about 5 minutes.