Comments of chapter undefined of The Forsaken Sovereign

There's been a confusion, maybe. Shadows aren't "dark memories," but they're corrupted, non-sentient (unless awakened) lifeforms that basically live in another plane of existence. You can liken them to doppelgängers experiencing the physical world through their owners' senses. Even if you alter an individual's memories, it won't affect their shadow, especially if you aren't aware of it.