The Ultimate Battle
From SmashWiki, the Super Smash Bros. wiki
The Ultimate Battle is a co-op event match in Super Smash Bros. for Wii U. Both players must choose a character and take on all playable fighters (excluding Mii Fighters and DLC characters) in the game. The order of the characters go from clones, to unlockable characters in Super Smash Bros. for Nintendo 3DS, third party characters, and starters. Each of these groups are ordered from newcomers to Brawl veterans, Melee veterans, and Smash 64 veterans.
10000G is awarded for clearing this event on hard difficulty.