Dark Emperor

The Dark Emperor (known as the Dark Lord in Europe and Australia) is a boss that first appeared in the StreetPass Mii Plaza game Find Mii II (StreetPass Quest in PAL regions). The Dark Emperor also appears in Super Smash Bros. for Nintendo 3DS as 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.