Blade of Marmora - The Figure in The Dark

After his father's death, Keiths mother takes him to join the Blade of Marmora, where he is raised and trained by the Garlas. The Palidians (Lance, Pidge, Hunk and Shiro), are still looking for the Red Lions' pilot - Allura is currently filling in, but she is not the true bonder, so her capabilities are limited. On one mission, the BoM and Voltron clash, with a mysterious figure leaving an impression on the Paladins. After the initial battle, more and more sightings of the strange individual occur, until BoM comes to Voltron with a request, sending the Mystery Galra over as proof of their good intentions.
In this AU, Keith can change his appearance to appear more human or Galra at will. Though in human form, he stills has longer and shaper teeth, and some distinct features of Galra.
Also, Lance gradually has a crush on Keith, but I don't know if Klance is going to happen in this story.
Allura is rude to Keith in this fanfic, so some characters may act out of character.
I don't own any of the characters listed above or are in this fanfic.
May contain mentions of abuse, violence, and is non canon.