Big Order

[shinta|hikari]

That's because he didn't order her to do specific stuff. What he did was prohibit her from doing something, which she is following perfectly. Even her attempts to accidentally kill him don't work by some magic, which might even be part of his power (but that's irrelevant).

Betrayal will work the same way, like you said. They'll want to betray him. They'll think it every single day. But they can't, just like she can't kill him. That should mean they can't take actions that will mean betrayal, just like how the girl can't take any actions that will mean the hero's death.

Don't forget that he ordered the girl to heal his sister, and she did so immediately.

How about an order like, "Do not do anything that will harm me in any way, shape, or form?" + "Give me your absolute loyalty and affection?"

Will that work? We don't know. Why? I have no idea.