This practice is called elo-boosting, and it goes against the terms of the contract that XiaoWeiXiao signed when he became a professional player of the LCS. (League Championship Series)
XiaWeiXiao has had his account suspended by Riot, the organization that owns and manages League of Legends and the LCS. XiaoWeiXiao plays for Team Impulse, and so far none of the other members of the team, or the team's manager, have come forward with an admission of guilt or wrongdoing.
As the investigation is conducted, XiaoWeiXiao will be removed from LCS play. It is expected that Team Impulse will suffer from his loss.
Which is great for me! Because my fantasy LCS matchup this week is against someone with XiaoWeiXiao on her team. Sweet.