Duon

Duon (, Duon) is the sixth boss encountered in The Subspace Emissary. He doesn't hail from any particular series, and is unique to Super Smash Bros. Brawl. He is created by several Shadow Bugs that have gathered in a single, very powerful being.

His name is derived from the Latin word duo, a word meaning twosome, or a group of two, alluding to his two-faced design.

Boss description
Duon is a two-sided robot on one set of wheels; one half is pink and has a head cannon and two arm cannons, and the other half is blue with two arm swords and a curved blade on his head. Both sides have shoulder exhaust pipes which rockets (pink side) or mines (blue side) can be fired from (though these can also be fired from the arm cannons). He rotates 180 degrees to change his attack strategy. The wheels he pivots on loosely resembles the Yin and Yang. There is an invisible platform between Duon's two halves, making Duon one of only two bosses that a character can actually stand on, the other being Porky Minch.

As a playable character

 * Main article: Duon (SSBB)

Like all Brawl bosses, Duon can be controlled in Boss Battles through hacking. The start button will self-destruct it.

Role in The Subspace Emissary
After, , and kick all the es out of the Halberd's control room, they fall to the bridge and dissolve into Shadow Bugs, which form into Duon, a last resort to defend the Halberd. The monster is confronted by Snake, Lucario,, /, , and (Meta Knight stays behind to retake his ship and does not take part in the fight). The boss battle makes up the entirety of the Battleship Halberd Bridge level. After Duon is defeated, it dissolves into Shadow Bugs and leaves behind the trophy of Mr. Game & Watch, which Peach revives.

Duon later reappears in The Great Maze and is refought by the playable characters.

Moveset
Like all bosses Duon is controllable with hacks in Boss Battles. The start button self-destructs any boss, while using Grapple Beam resets them to AI control.

HP and damage taken
Like all bosses in Brawl, Duon gains an additional ×0.6 damage resistance modifier when fought in co-op mode, effectively gaining 67% more health. This modifier is applied whenever the second player is in-game, and is removed if the second player loses all their stocks.

Trophy
Duon's trophy is obtained by using a Trophy Stand on it during the boss fight.

Spirit
Duon appears in Super Smash Bros. Ultimate as an Advanced-class primary spirit.

In Adventure Mode: World of Light, Duon is presumably one of the countless spirits captured by Galeem during his takeover of the universe. Duon's spirit is located in the Base sub-dungeon of The Light Realm.

Duon's Spirit Battle uses a giant puppet fighter starting off with a Super Scope, referencing Duon's dual sides and its pink side's built-in laser blasters, and is fought on the Halberd stage's ship deck layout. During the battle, Shooting Type items will appear, further referencing Duon's pink side's shooting attacks.

Trivia

 * Duon is the only boss that can hurt himself without the aid of items or a reflector.
 * It is possible to stand on Duon, between the two heads, although this serves little practical application as Duon still has attacks that can hit the player in this position, while the space for the player to maneuver on is very limited.
 * 's Homing Attack will always home in on Duon's pink side.
 * The word "DUON" is hidden on his wheels. This can be more closely seen when examined as a trophy or when using mods that remove the ingame camera limitations.
 * Duon shares a resemblance to bosses from other series represented in Smash.
 * If Duon is defeated while performing its Vacuum Spin attack, it will finish the attack before beginning its defeat animation. However the player cannot be KO'd in this state, as the blastzones cease to exist the instant Duon's health is fully depleted.

Duon