Guardian Angels are actually the ones that rebelled against God, because they hated the suffering of man. God set things in motion, and demanded no interference, but not everyone agreed. They got sent to Earth as punishment, and mostly exist in a plane between worlds. Occasionally, a Fallen Angel will create an attachment to a person or group of people, and prevent death or destruction, but if it's too obvious they will get hunted down and punished further. Sometimes their prevention makes things better, but sometimes it makes things worse. Everyone is trying to understand how The Tapestry works, aka The Grand Plan. Some think that God hides it from everyone, but the elite, others believe it doesn't exist, and God is just winging it. When Guardian Angels get punished they become ghosts, of sorts, the only expressions they have left are vague feelings, vibrations, smells, cold drafts, unless they were very powerful to start with, and they're fucking angry, and then watch out.