Egon is a King's Ranger in time that King Oswald still reigned. He appears in The Tournament at Gorlan, and also in The Battle of Hackham Heath; while he is present there, the latter book never actually mentions his name.
The Tournament at Gorlan Edit
We came to know Egon when Crowley found him in a bar at a Seacliff Fief Inn. He was found drinking Brandywine, a potent wine. Crowley talks to Egon In the Inn. Egon gets mad and pulls out his Saxe on Crowley. Crowley dodges the Knife and subdues Egon. He then takes Egon back to the rest of the group and introduces him to them.
Egon later on goes around another group of Rangers led by Samdash. He gets around them and makes them surrender. Crowley then convinces them to join their group.