User blog comment:Tommy,Klaus&Kol2012+/spn questions/@comment-3481504-20141222062624

1) Besides a righteous bone washed in the three bloods of the fallen (and Death's scythe), God, Death and archangels can kill Leviathan.

2) They're like tulpas, the rigorousness of human thought created them.

3) God.

4) Nothing, God just is.

5). The Horsemen came into existence when their concepts occurred, but this might not apply to Death.

6) For plot survival.

7) Power and/or age.

8) For his story.

9) Dick isn't their alpha, because he didn't create them, but he is the oldest Leviathan.

10) The Kurds (as now revealed in season eight).

11) Easily.