[quote=@Weird Tales]
<Snipped quote by The Grey Dust>

Well part of his powers involve summoning spirits to the plain he is currently in so his god allows spirits to break the barriers between dimensions to be summoned 

[/quote]

The gods have no "real" power in hell, nor do the "Dukes" of Hell. The real powers which write the Rules of hell belong to a third party which represent forces beyond the grasp of the gods :P. However your god can break the dimensional walls to let spirits in, but getting them out requires something more... innovative as Hell allows spirits to enter, but never to leave.