Board Thread:General Discussion/@comment-71.180.122.196-20130713222416/@comment-29458028-20140819102452

There are multiple Alduins in the code. There is the invincible one that spawns at Helgen and the dragon graves, the essential one at the throat of the world and the killable one at Sovengarde. Each one is activated and disabled accordingly, the joker who spawned the three Alduins spawned the invincible ones.