Mii Fighter (SSBU)
Mii Fighters (Miiファイター, Mii Fighters) are playable characters in Super Smash Bros. Ultimate. They were confirmed as playable characters on June 12th, 2018 with their Brawler, Swordfighter, and Gunner variants returning. Unlike in Smash 4, fully customizable Mii Fighters are now usable in online play against anybody in Quickplay, rather than just friends. The Brawler, Swordfighter and Gunner are classified as fighters #51, #52, and #53 respectively.
The Mii Fighters have twelve different voice options, with all but two provided by a different voice actor: Yūji Kishi (Voice 1), Umeka Shōji (Voice 2 & 12), Takashi Ōhara (Voice 3), Ayumi Fujimura (Voice 4), Ryōtarō Okiayu (Voice 5), Makiko Ōmoto (Voice 6), Michihiko Hagi (Voice 7), Minami Takayama (Voice 8), Hideo Ishikawa (Voice 9), Kimiko Saitō (Voice 10), and Kiyoyuki Yanada (Voice 11). There is also an option for them to be silent, as they were in Smash 4.
Changes from Super Smash Bros. 4
The Mii Fighters were formerly considered some of the most volatile and situational characters in SSB4, due to their heavy reliance on customization to compensate for their lacking default movesets, which also made them infamous for their legality in tournaments. Likely as a result of these factors, the Mii Fighters have been given significant changes in the transition to Ultimate.
One of the biggest changes involve them now having fixed attributes for each type of Mii Fighter, which streamlines their previously height and weight-dependent stats: the Mii Brawler is now the lightest and fastest, the Mii Gunner is the slowest and heaviest, and the Mii Swordfighter is the middle ground of the two. In addition, their standard attacks have been made more reliable through a reduction of lag, and the majority of their extensive special moves have been heavily modified to have enhanced speed, combo potential or power, or even replaced by completely new attacks. Most notably, the Mii Fighters' default special moves have been given a variety of buffs to make their KO or combo potential surprisingly high, meaning that they can now function equally as well with only their default moveset; this also eliminates their previous weakness of situational default moves with low KO potential.
However, the Mii Fighters have also been nerfed indirectly. Their new fixed attributes give each of them a new specific weakness; for example, the Mii Brawler is now a fast-falling middleweight that is easy to both combo and KO, the Mii Swordfighter's average stats give it no advantage apart from airspeed, and the Mii Gunner now lacks in mobility. Additionally, they retain noteworthy weaknesses from Smash 4, such as the Mii Swordfighter having a mediocre disjointed range for a swordsman, the Mii Brawler still having a short reach, and the Mii Gunner having very slow mobility and attacks with high ending lag.
Overall, the Mii Fighters now fare significantly better and have been repurposed to perform more consistently with or without customization, especially when compared to their SSB4 iteration with default custom moves. While their unique access to custom moves now make them tournament legal, their general lack of representation and results have made it difficult to determine their standings in the metagame.