I feel the power theft is relatively unique compared to the generic power drain, given she still has standard levels of power (so it didn't drain everything she has, and doesn't seem to be a seal), and messing with those memories in particular.
I can only hope the king and his daughter will see something horribly wrong with how their original saintess had her engagement anulled and exiled by her (ex)fiance, the prince.
Ooh, I hope you guys keep translating this! I love these sorts of abandoned saintess stories. You guys did a great job with the TL work and typesetting too!