6. Celestials
Knowhere is the head of a fallen Celestial (what was powerful enough to kill and behead one of them isn’t revealed), though we also get to see one in action when The Collector explains the significance of the Infinity Stones to the Guardians of the Galaxy. Created by the legendary Jack Kirby, The Celestials existed at the birth of the universe and created life and death along with the multiverse (alternate realities basically). Many of these exist and they all serve different purposes, and if you think Thanos is bad, even The Avengers and Guardians of the Galaxy combined would struggle to take one of these guys down. However, the significance of them being introduced here is huge and it would be very surprising if they’re not used again in the Marvel Cinematic Universe.
