A Boss is a Mii who you face at the end of a level in Swordplay Showdown. They are the hardest Mii of a level and need to be defeated to finish a level. No boss is seen on any other level. They have 3 hearts, wield purple swords, and wear Black Armor, which has 3 different designs: Bulky, Obese, and Lanky.
The Obese Armor is worn by Miguel, Marco, Takashi, Ian and Steph and looks like a round fat person with big legs. The Bulky Armor is worn by Cole, Gabriele, Barbara, Fritz and Matt and looks like they have regular bodies but have the big legs. The Lanky Armor is worn by Gabi, Alisha, Hiromasa, Sarah, Asami, Anna, Tomoko, Marisa, Shinta and Yoko and looks like a very skinny swordfighter with very skinny legs. Starting on Level 10, the boss will be very defensive and will strike often. After Level 18, the boss (Fritz, Yoko, or Matt) starts to defend himself/herself if he/she fails to attack. In these cases, it is especially essential if you reach the boss with all 3 hearts.
Bosses in each level:
- Cole (Level 1) (Skill level: 431+)
- Gabi (Level 2) (Skill level: 1451+ [4th best])
- Miguel (Level 3) (Skill level: 941+)
- Alisha (Level 4) (Skill level: 326+)
- Hiromasa (Level 5) (Skill level: 221+)
- Sarah (Level 6) (Skill level: 521+)
- Marco (Level 7) (Skill level: 1121+) (Pro)
- Asami (Level 8) (Skill level: 71+ [5th worst])
- Anna (Level 9) (Skill level: 1481+ (Vice Champion))
- Gabriele (Level 10) (Skill level: 266+)
- Tomoko (Level 11) (Skill level: 236+)
- Takashi (Level 12) (Skill level: 1376+ [9th best])
- Marisa (Level 13) (Skill level: 641+)
- Ian (Level 14) (Skill level:161+ [11th worst])
- Barbara (Level 15) (Skill level: 536+)
- Shinta (Level 16) (Skill level: 1421+ [6th best])
- Steph (Level 17) (Skill level: 626+)
- Fritz (Level 18) (Skill level: 731+)
- Yoko (Level 19) (Skill level: 881+)
- Matt (Level 20) (Skill level: 1496+ (Champion))
- Despite Matt being both the champion of Duel/Speed Slice as well as the Boss of Level 20, a Mii's role as a boss is otherwise not symbolic of their skill level in Duel and Speed Slice, as each boss's skill varies. For example, Asami, the boss of level 8, is very bad at Swordplay Duel with a skill level of 75; while Gabi, the boss of level 2, is a top PRO with a skill level of around 1455.
- In some later stages, there are Miis that look and behave exactly like the bosses do, wearing the same black armor and being just as defensive and offensive, but are not actually bosses. Examples of this are Eva and Abe in Level 10, who appear alongside the actual boss of the stage, Gabriele. The only difference between those non-boss Miis and the actual boss Miis are that the non-boss Miis have the same red sword as all the other enemies as opposed to the boss' purple swords, while the non-boss Miis are not always the same size as the boss. These types of enemies have a total of 4 variants, just like the bosses: Small, Small Thin, Lanky and Bulky.
- Miguel is the only Boss out of them all that does not block when he gets near the player. Instead, he drags his sword onto the floor while holding it on the area where his pelvis is. He does block when he spawns in, but as soon as he gets really close to the player, he stops blocking and starts dragging his sword onto the floor.
- Ian, despite being a boss, appears as a Green Armored opponent in the picture used as a preview in Swordplay Showdown.
- Alisha is the only boss that attacks you twice in a row if you let her hit you.
- Tomoko exhibits this behavior, albeit periodically.
- Hiromasa and Gabi are the only two bosses in the Normal Stages to be a bit more aggressive, as they attack more quickly and swing their swords a bit more frantically than the other Swordplay Showdown bosses in the Normal Stages.
- Starting from Fritz, the bosses will defend themselves immediately after failing to attack.
- Hiromasa and Shinta are the only Male Bosses to wear a different type of Black Armor from the rest of the Male Bosses. Barbara and Steph have the same case, being the only Female Bosses to wear a different type of Black Armor from the rest of the Female Bosses.
- Yoko is the only Female Boss to defend herself after failing to attack.
- The Obese and Bulky Black Armored Bosses share the same legs.
- Miguel is the 4th best before being pro in swordplay and Gabi is the 4th best pro in swordplay.
- Ian is the only boss whose favorite color is lime green.
- Cole is the only anti-pro boss in Showdown.