For quite a while now people have been speculating on how the Inhumans could be introduced to the MCU and how. After watching the AOS finale I have come with my own theory.
Skye:
Ever since the revalation that Skye once exhibited superpowers people have been speculating on who she would become, if anyone. I personally thought she wouldn't become any character from the comics however, I do believe her Father is someone.
So far all we now of Skye's father is he likes to sit Ina bath of blood. But do we even know that? His hand appeared to be scarred or burned when holding that photo whose to say it's not his blood. Or maybe the tub isn't a tub at all but a device that is keeping him alive. Now I don't know how that would work but there is a certain MAD inhuman who could design a machine that could do just that.
Maximus the Mad. Brother of the king Black Bolt and total psycho. Now in the comics he works with his brother and creates weapons for the Inhumans. But that wasn't always the case. He originally worked against his brother and tried to work with the Kree to overthrow his brother. That's already a connection the Inhumans have to the MCU, the Kree. They are the being responsible for the Inhumans as their genetic experiments are what created the Inhumans. Back to Maximus his powers are his genius level intellect and mind controlling abilities. Now this doesn't sound like the murdering monster mentioned in AOS but if they tweak his powers so he kills people by reaching to their brains you've got your monster. The reason he could be chasing down Skye is to subject her to the terrigen mist and use her as a weapon to fight his brother Black Bolt. The reason for this could be that she wasn't completely subjected the last time father and daughter were together meaning Skye's only display of power will remain her only display of power until the most awkward family reunion ever. I expect the reason Maximus is in some random building in the world is, after the inhuman royal family was alerted to the killing spree he led in search of his they cast him out of Attilan and left him on earth with a broken body(hence why he'd need to be healed).
Now I know this theory may sound as mad as Maximus but I believe it could work. However do you think it could work? Or do you have an alternative theory? Let me know in the comments.