Board Thread:Lore Discussion/@comment-26400653-20150608022111/@comment-26400653-20150608185501

WrathOfHircine wrote: Well, I don't think alduin is realy dead, you know you don't absorb his soul but it is a good start for the fifth era.

If I remember correctly because you killed Alduin in Sovngarde his soul was obliterated, and that is why you didn't absorb his soul.