>>27073519>Like, demon-Sunset isn't an evil Sunset that lives in her mind, it's just... Sunset, with the Element of Harmony that's warped wrong.
Nicely worded. And I agree. It's not just something cheap like an evil alter ego living inside her. It's just the bad parts of a misguided girl further enhanced. >>27073519>>27073542>Questions.
Now, see it from two angles.
One, the show. Where Celestia emphasises that the Elements are "always with them (their bearers)".
Two, /pa/. In which an heir without ascension in possession of such raw mental power it keeps spilling out and messing with her and those around her encounters something apparently unnatural and powerful and locks part of that mentality away.
Also, three, which will be important in a moment. Her massive loss of important memories.
And then you end up with the reasonable explanation why a) Sunset can call on far more power than she should be, considering her counterpart is an alicorn and b) she is starting to get more and more unhinged due a mixture of losing part of herself to two different external sources.
/pa/ can be magic like that.