For a start, you don't even know which comments are mine. Or I supposed that you think everybody is always the same person?
Second, "foreshadowing and similarly subdued scenes of development" isn't a qualification for being a mary sue. That's just how a story unfolds.
There was en entire episode centered on Yoko being jealous and hateful of Nia because she was perfect at everything. How about you just accept things for what they fucking are.