4. Loki (Thor, The Avengers)
Tom Hiddleston’s Loki was the MCU’s first great villain. His trickery and charismatic skills made him stand out during Phase 1. Like in the comics, he was the first villain that the Avengers faced, and he did not fail to disappoint. The low point of his evilness came when he murdered Phil Coulson right in front of Thor during The Avengers.
After Phase 1, Loki’s character went through somewhat of a change, which is why I don’t have him higher on this list. He would fight alongside Thor on occasions. Of course, Odinson always knew that Loki could turn on him, which he usually did. One of the things I’m excited about in Phase 4 is his series that will stream on Disney+.