Complex sentence: The show also features angels possessing humans similar to demons, but unlike demons, angels need the people they are possessing's permission and as shown in season 9's "Road Trip", can kick the angel out if they no longer wish to be possessed.
Split into simpler sentences: The show also features angels possessing humans similar to demons, but unlike demons, angels need the people they are possessing's permission. As shown in season 9's "Road Trip", the possessed person can kick the angel out if they no longer wish to be possessed.