As far as I read, I haven't seen any SD (security devil) betrayed their master. Maybe because their relationship is based on "trust". (There are specific chapter talking about this "trust")
In Opera case, they decide to become Sullivan's SD because they trust him, meaning, Opera choose Sullivan themselves. ((sorry if it sounds weird))) It's unique tho, somehow it feels like security devil is not just a regular underling, because, Opera choose to be it, not being chosen by Sullivan.
I'm curious about other SD, it would be interesting if other than Opera have different reason to be a security devil. Somehow I started to like this Master-Security Devil dynamics (?)














