Board Thread:Lore Discussion/@comment-26316533-20150724175957/@comment-177.34.181.193-20150903002951

They can't really be "killed". If either Aedra or Daedra dies in Nirn, they will just return to Oblivion(in case of Daedra) or to it's plane/planet within Mundus(in case of Aedra).