Board Thread:Questions and Answers/@comment-1031724-20161029080114/@comment-27020644-20161110034053

Thanos really isn't a one shot. He was behind the Chitauri Invasion, Ronin aquiring the Power Stone, Ultron's anhiliation plans, then Avengers: Infinity War and Avengers 4.

Thanos is a threat that is too dangerous to let live, and since they aren't doing an Illuminati story line, the Infinity Stones will likely be destroyed so he wont be after them. Plus with him dead, they can move on to focus on Dormammu or some other great threat.

Also, how do you know all phase 3 villains will live? As far as I know, starting with Spider-Man: Homecoming, each movie will have about 3 main villains. I doubt they'll let every villain live. Right now you're bassing that theory off of 2 out of 10 movies.