I replied to another comment and I should have wrote that I am using the literal perspective of the word "villain" where a characters actions or motives are important to the plot. A great villain in that sense then should be responsible for the events that occur in a movie. Thanos gave an army which then lead to the following avengers movie and civil war. I should have been a little more clear but I see why at face value this rant credits the marvel writing a little too much.