The people of the Demon Realm are very pragmatic; integrity is almost nonexistent for them.

If you're stronger than them, you can oppress and humiliate them at will. If you're weaker, even if you've done them a great favor, they will betray you without hesitation.

Even Helian, the Demon Empress, is no exception.

She quickly accepted reality. Now that she's a prisoner, she doesn't expect to be treated normally.