Mario

Mario is the main and titular protagonist of Nintendo's flagship Mario franchise. Since his debut in the 1981 arcade game, Donkey Kong, Mario has appeared in hundreds of video games, making him one of the most recognizable video game characters. He is playable in every Super Smash Bros. game along with his younger brother, Luigi. Mario is portrayed by Charles Martinet in most media, including the Super Smash Bros. series.

In the Mario franchise, Mario can take on several forms through the use of power-ups. In the Super Smash Bros. series, Mario has two counterparts, Metal Mario and Dr. Mario. The former is a specific opponent in some Super Smash Bros. titles, and the latter is a standalone fighter in some Super Smash Bros. titles and has a moveset based on Mario's.

Role in The Subspace Emissary
In Super Smash Bros. Brawl's The Subspace Emissary mode, Mario first appears in the first stage, Midair Stadium, where he fights Kirby after both spawn from their trophy. The player can choose which character to play as, making the other one the opponent. After the battle, a cutscene shows the winning fighter reviving the losing one from their trophy before waving to the audience. The Halberd suddenly appears and unleashes an attack on the Midair Stadium. Peach and Zelda join Mario and Kirby to try and defend the stadium, but while doing so, Mario gets hit by a cannonball, causing him to fly out of the Midair Stadium.

Later on, it is found that Mario had landed in Skyworld. He teams up with an angel named Pit, and the two of them go to pursue after the Halberd and the Ancient Minister.

In a later stage, Mario and Pit encounter Link and Yoshi, and they get into a misunderstanding involving Peach and Zelda. After the ensuing fight, King Dedede takes the trophies of the two losing fighters to put on his Cargo, but Kirby appears and revives the fighters. They go after King Dedede and eventually meet up with all the other fighters near the end to journey through Subspace and engage in a final battle against Tabuu.

Trivia

 * Mario's stage entrance shows him jumping out of a Warp Pipe while saying, "Let's-a Go!".