The player must have a controller in slot 3, or Master Hand cannot be controlled. It is much easier to do if there is only one name entered. Using this controller, place the cursor over the name field on the character selection screen.

How do you fight Master Hand?

Damage one Hand first and when they are stunned, use this time to focus on the other boss. Deal damage to them, rinse and repeat. Each boss gets stunned twice (once towards the middle of their health bar, and once towards the end), so staggering which Hand you attack maximizes time fighting a Hand solo.

Is Master Hand good or bad?

Indeed, his trophy suggests that Master Hand himself is not inherently evil, or he disliked the fact that there was someone stronger than him.