More lore info:

Rift: Planes of Telara Reader Submitted Q&A #5 Lore (Ten Ton Hammer)

Nicholas Taylor McDowell: As Lore Lead for the Guardians, Im going to say that the Defiant are completely evil! (laughs)

Lindsay Morgan Lockhart: As Lore Lead for the Defiant, Im going to say that the Guardians are completely incompetent. (laughs)