Developed by Radiant Entertainment (Rising Thunder)
During Riot’s livestream, the developer showed early development footage of the League fighting game, including champions Jinx, Katarina, Darius, and Ahri fighting in 2D environments. The fighting game will show Runeterran champions “in a new light,” Riot said.

While the fighting game has been in development for some time, Riot said it’s “a good ways towards making something that we think is really cool, [but] we still have a long way to go.”

“Project L” has been long rumored since Riot acquired Radiant Entertainment, which previously worked on the PC fighting game called Rising Thunder. That game featured giant robots battling in one-on-one fights, and pursued a simplified approach to the complicated move inputs seen in other fighting games.
https://www.polygon.com/2019/10/15/2...t-l-riot-games