Complex sentence: His channel first drew attention during the Gamergate controversy in 2014, when he argued in one of his videos that members of the Digital Games Research Association (DiGRA) were actively plotting to influence video game development to conform to their "ideological feminist agenda".
Split into simpler sentences: His channel first drew attention during the Gamergate controversy in 2014. His videos have advanced a conspiracy theory that members of the Digital Games Research Association (DiGRA) were actively plotting to influence video game development to conform to their "ideological feminist agenda".