Gregory's plan was simple.
He needed to find a way to get to Arwen and somehow force out the entity that was trying to replace her existence.
But all things considered, there was no way the banshees in the Wailing Peaks would allow him to do such a thing.
From what he understood, the person taking over Arwen's body was an ancestor of the banshees from the third era, a figure that had the grand desire to conquer death and free the banshees from the Callings.
But as grand as that goal was, Gregory couldn't allow his daughter to be the sacrificial lamb of that person's return.
He'd much rather take her place, at least, that way, Arwen would be able to keep on living.
Having made a lot of mistakes in his life, he felt this would be his chance to do something for Arwen after abandoning her for all these years.
