Summoned Demons and Death:

[Hervé]

I'll say that in the Howard novels, everything can die, man, beast, demon or god... They don't go back anywhere, except to the pits of Aralu!
Sharing a same base game system is the only common point between Conan and D&D. Pushing the comparison further will be a big mistake on what the game really is.

my two cents.

 

[rabindranath72]

Unless it's a player character who is Summoned, I would say just wing it! Who cares where/what a demon or other creature goes/does after the summoning?