If you did not know, Riot Games recently became a full subsidiary of China’s Tencent. Even before the deal was done, Tencent, as the majority shareholder, begun pursuing lawsuits against Chinese studios which made use of champions from League of Legends to make non-official mobile games (IP infringement). Recently, a list of known lawsuits were made public, as seen in the list below.
Some cases have already been settled, with the more popular studios being Chukong Technologies (owner of the popular Cocos2d-x game development platform) and ZQGame. Since 2014, the Chinese government has been actively trying to help companies clamp down on IP infringement and brand copyright cases. Just a note, there is currently no official League of Legends mobile game.