How many champions are in 2XKO?

When Riot Games announced 2XKO, called by its codename Project L back then, people immediately started fantasizing about which League of Legends characters would fit a fighting game better.

There’s Lee Sin, a blind monk who fights with kicks and punches. Sett, a literal brawler from the arena. Riven, whose entire League of Legends moveset was based on Marth from Super Smash Bros.