Unholy Guarding (Stronghold Augmentation)

Unholy Guarding: When creating this augmentation, choose one face of the wall. Any evil character on the chosen side of the wall (or standing atop the wall) gains a +4 deflection bonus to AC and a +4 resistance bonus on saves. They also gain spell resistance 25 against good spells and spells cast by good creatures. Furthermore, they are protected from possession and mental influence as per protection from good.
Caster Level: 15th; Prerequisites: Craft Wondrous Item, unholy aura; Market Price: 50,000 gp.