Well...its not normally an effect that effects an area, it affects creatures.
In any event,
Constant +4 deflection versus good aligned opponents*
Successful melee touch attack against good aligned outsiders forces them to home plane if desired, negate by touch attack. Using this temporarily ends the spell for 10 mins.
Touch attack can dispel one enchantment cast by an good creature or a spell with the good sub type. Spells that can't be dispelled by dispel magic cannot be dispelled by dispel good. Saving throws do not apply. Using this temporarily ends the spell for 10 mins.
Temporarily ending the spell negates the deflection bonus until it resets after 10 mins.
Adjust the time to be whatever you like. I would suggest a minimum of 1 minute. Any more and the effect it something that could be taken advantage of multiple times in combat which could be very overpowering.