Okie just came to a realisation (Some Spoilers Here for Shadowlands)
When Uther was killed his soul was split right? One half went into Frostmourne and the other to Bastion.
When Sylvanas was killed, part of her soul would have went into Froustmourne and was then forcibly returned to her body to change her into a Banshee.
But that leaves the other half of her soul...
So my theory is that somewhere in the Shadolwnads is the other half of Sylvanas’s Soul. It could explain why Sylvanas feels nothing but anger and hatred. Like for example the other half of her soul in Shadowlands is the one that can feel love, and happiness.
Will the two halves join back together? Will it restore her to her alive state? Will Sylvanas have redemption and be whole again? Does Sylvanas know this already and is trying to find her other half? Who knows, but this is just my speculation dump.
(edit) Just gonna add to this, recently some new soundtracks for Shadowands were released and one of them is titled “Sylvanas Free Will”. This may be hinting at something also. Another notable mention is that it’s 11 minutes long! And in my opinion a really beautiful piece. The tone of the song shifts from an ominous to a more triumph/happy sort of vibe at the end, so make with that what you will.
