Play as some of your favorite Pokémon in Pokkén Tournament, the first ever Pokémon fighting game for the Wii U by Namco Bandai.
From the game's Wikipedia page:
"Pokkén Tournament is a fighting game developed by Bandai Namco Entertainment. The game combines gameplay elements from Bandai Namco's Tekken series with characters from the Pokémon franchise, inspiring the portmanteau title Pokkén. It was released for Japanese arcades in July 2015, and worldwide for the Wii U in March 2016. An enhanced port for the Nintendo Switch, Pokkén Tournament DX, was released in September 2017. The arcade version was published by Bandai Namco, the Japanese console versions were published by The Pokémon Company, and the console versions outside of Japan were published by Nintendo.
Pokkén Tournament is a fighting game in whichever two fighters battle against each other using various Pokémon, with gameplay shifting between "Field Phase" where the Pokémon move freely around the arena similar to Power Stone and Naruto: Ultimate Ninja Storm, and "Duel Phase" where they move relative to each other similar to the Tekken games. Unlike most arcade fighting games, which use a traditional joystick and buttons, the arcade version is played using console-style controllers, which are designed so that players who are not used to arcade sticks can get into the game more easily. The game focuses more on action, as opposed to the more technical gameplay of Tekken, allowing both hardcore and casual fans to enjoy it. As such, players can perform various techniques taken from the Pokémon series, such as special moves and Mega Evolutions (which can be built up from attacks using a "Synergy Gauge"). Players can also use Support Pokémon to give them special benefits such as buffs in attack or defense. First-print Wii U copies of the game were packaged with a Shadow Mewtwo Amiibo card, which immediately unlocked the character for use. The title also features online play..."