From :

Joss Whedon kicked off the Thanos hype by directing The Mad Titan’s first MCU appearance in The Avengers. That mid-credits scene remains one of the most exciting moments in Marvel Studios history, even if Whedon wasn’t sure how to properly pay it off at the time.

While speaking with IGN, Whedon admitted that he was not really sure what to do with Thanos, even after showing the character again in Avengers: Age of Ultron. He was, however, quite pleased with what directors Joe and Anthony Russo and writers Christopher Markus and Stephen McFeely turned in for Avengers: Infinity War.

Read the Full Story