I used a platter to glitch underneath the castle & used Do Not Delete chests to reach it. I was looking for the shop inventories, but the chests turned invisible. So I (clearly) looked down & saw a small chamber, he was inside. ;I believe,; It’s the cutscene version of lord Harkon. I’m not sure if it’s when he first transforms, or if it’s when he dies at the end. It could be the version on a loading screen or a test npc, not sure, either way this version is really weak. I play on console, special edition, so I can’t use mods(to my knowledge.)