Sinh, the Slumbering Dragon, the final boss of Dark Souls II's Crown of the Sunken King DLC, is one of the series' most exciting boss battles. It's a battle that needs something similarly cool as background. Vaati, a Souls veteran, helps us decode the game's cryptic backstory with a masterfully crafted lore video.
Here's the video. The editing and narration are superb (it's easy to get chills), there's some speculation, and it all ends on an ominous note. It's also full of spoilers for Dark Souls II and its first DLC, Crown of the Sunken King, so watch out:
Dark Souls 2 Story - Sinh, The Slumbering Dragon [VaatiVidya, YouTube]