Dark Emperor

The Dark Emperor is a boss who first appeared in the StreetPass Mii Plaza game Find Mii II (StreetPass Quest in PAL regions). In Super Smash Bros. for Nintendo 3DS, the Dark Emperor is a boss in the stage Find Mii, where he will first appear in the background and can either increase or decrease the stats of at least one fighter, or cause either of the stage's two platforms to temporarily sink. However, he also may go the foreground and can attack fighters in contact, but if one manages to defeat the Dark Emperor by dealing enough damage to him, they will get a stat increase and the Dark Emperor will leave the foreground.

There is a trophy of the Dark Emperor in Super Smash Bros. for Nintendo 3DS, and it is obtained by battling three or more times on the Find Mii stage.