Mewtwo is no longer a character so you can't fight him in ssbb.
People can fight the top fight out of all
Choose him during a fight
There really is no strongest character. It depends on how you fight.
Nope. You can fight him, though.
You can fight Master Hand in boss mode
mewto
you need to get to the end of adventure mode when you fight tabuu
You fight the master hand or crazy hand on Stage 12 in Super Smash Bros. Brawl.
If you mean fight them, yes. If you mean play as them, no.
You can catch MEWTWO ,not Mewto, at the end of Cerulean cave
No you can enter the door after you have completed the great maze
he is in the water area with all the cannons. go through the middle door and fight him.