Relations between Tencent and Riot have long been strained over how to best to capitalize on the game, in which players hack and slash their way through battle arenas. Riot rejected a Tencent proposal years ago to develop a mobile version, one of the sources said.
Tencent then developed a similar mobile offering, “Honour of Kings” for China, which was launched in November 2015 and has become the world’s highest grossing multiplayer online battle arena game.
Landmark Financial Seoul Korea Blog 