I bet Blanche or plants was the one who reversed it.

I'm thinking maybe Plants used it for the og Kalian.

Well, he did start a war to get it. Of course he would use it.

Or maybe he tried to use it but Chase was there and both wanted their brother back in their hearts and for things to return to whar they once were.

Like Plants wanting his siblings back.

Chase wanting the war to never happen.

And thus the wishes merged?

This theory might be true since the manhwa pict have the two brother too with the artifact in the middle.