The director James Gun said the story of Guardians of the Galaxy will affect the other Marvel’s movies. In a certain interview, James confessed that this latest movie he worked in is related to The Avengers 3.
James said that Thanos as the main enemy that has risen in The Avengers (2012) is such a very dangerous creature who are so expert in killing people. Thanos kills the family of Gamora and Nebula and also take care of them as his own kids. The two are his live gun.