The Ace of Trainers is an independent international battle tournament series held in mainline Suocéverse during the 3700s. The tournament is inspired by, and the name derived from, the The King of Fighters videogame franchise and the eponymous in-universe tournament.

“Ace_Trainer” is an official category of Trainers in the mainline games.

Depending on the host, the tournament is held as a single-elimination team tournament. A team, usually representing a country or region, consists of three Trainers with four Pokémon each, where in a battle up to three Pokémon are sent out to fight.

The tournament is held usually once a year or once every two to four years, with the largest gap being the absence of the tournament between 3732 PE^{(~1 before Gen1)} and 3734.

Unlike its source inspiration, the Ace of Trainers tournament is not (usually) used as the front of an evil team plot or as the gateway to some sort of apocalypse.

The following characters are known to have participated in the tournament at one point:

• Ravir Eisenhorth (Team Suocé) from approx. 3724 to 3737.
• Giorgio Sinde (Team Suocé) in 3735.
• Miria Eygliz (Team Emisre) from approx. 3726 to 3730.
• Miria Eygliz (independent) in 3737.
• Sílbira Highvelter (Team Dalacia) from approx. 3724 to 3728.