Re: How Do You Introduce S.W.O.R.D in the MCU.
I thought you'd never ask.
Marvel films have already mentioned in the Avengers and Thor that Thor's arrival was a major game changer. He is seen as an alien, more powerful then an army of humans. Fury said that he scared them, that is why they were creating weapons based on Hydra's guns made from the Cosmic Cube. They were afraid, and then Loki (another "alien") shows up and brings an army of aliens to attack.
So I see Fury creating a new branch of SHIELD called SWORD. It is SHIELD's and Earth's 1st line of defense against aliens. All started because of the alien attack on New York. Its headed by Abigale Brande and includes former pilot and SHIELD agent, now SWORD agent, Carol Danvers.