Shadowlord and Pirate King by Footloose, mushroomtale
https://archiveofourown.org/works/957967
Slash Merlin/Arthur
with amazing artwork at: https://archiveofourown.org/works/958021/chapters/1875898

I loved it,this is an excellent story. A very different take on Merlin while still sticking to the heart of the story. Let me say that this is a different Merlin then you are used to. He is one BAMF, an assassin, most importantly the last shadowlord. When he first meets the pirate king Arthur well let's just say it doesn't go well and actually gets worse before it gets better. There is plenty of snarky comments, diva attitudes and space battles galore. Of course there is a prophecy and the two must unite to save the clans. Arthur is desperately trying to keep his father alive and would make a deal with the devil. There are a lot of awesome scenes but the one that sticks in my mind even now is when Merlin is walking along the table in front of the the others as he approaches Arthur. It’s been almost two years since I read this, it’s cold and dreary outside perfect time to snuggle up with hot chocolate, cookies, and a story that will take you to another world.