Chapter Seven
In the beginning after the Archangels were formed and other beings were beginning to come to life, the Almighty came up with the idea of bonds. He sent out his Archangels to teach the fledglings their roles and sometimes the fledglings and one of the Archangels had a bond form that set protectiveness into overdrive for the Archangels. Over time the bond faded as the fledgling learned to protect itself.
The Almighty proclaimed this type of bond the Guardian Bond that could between all types of Angels and another of His creation. As humans were introduced to creation, certain Angels created bonds with their charges which made these certain Angels Guardian Angels that protected their charge until their purpose was fulfilled.
But no guardian bonds were ever formed between an Archangel and a human, in fact the last time an Archangel had a bond, it was between Raphael and their newest fledgling Castiel.
There were other types of bonds of course. Sibling bonds, garrison bonds, and more.
Guardian bonds were the most sacred as they were the first ones to happen and they connected them deeply to their charge the most.
No one knows how the guardian bond is formed besides the Almighty, of course. But those that receive them cherishes it until is gone.
One of the most sacred rules of all Angels is that no Angel can harm another Angel's charge.