Tiberius
Explorer
AuraSeer said:Relying only on your party's abilities, the only thing that comes to mind is Forbiddance. It's 6th level, well within your cleric's abilities, and has Permanent duration. The affected area is limited, but at least you can use it on your stronghold to prevent the baddies from warping in and killing you in your sleep.
Until said baddie decides to slap the Forbiddance with a Dispel, Greater Dispel or, if you are extremely unfortunate, Splendid Dispel. Then they kill you in your sleep.

-Tiberius