The man who guards the bridge between worlds and can see all of them at once, which makes him the loneliest job in Asgard.
Heimdall is the sentry, and the character the Thor films use whenever they need somebody to be right early. He sees across all Nine Realms, hears everything in them, and is therefore the first to know when something is wrong and the last to be listened to about it.
Idris Elba plays him in six films across seven years, mostly in short scenes. The best of them is in Ragnarok, where the guardian of the bridge is a fugitive leading refugees through tunnels, which is the same job with the grandeur taken off.