When Banshee rescued me and I was back in Muir Island, I was so relieved. I was finally back in a familiar place and among friends; or so I believed. Soon the Reavers came and caused more pain and destruction. And when that was over, I was trapped by Legion in the cell that once belonged to Moira's son, Proteus.
The powers I had acquired in the Savage Land were still new to me, and I did not have a hold on them; but David did, and he was using them to infest Muir Island with negative energies and influence everyone's minds, especially Moira's.
What I realized later was that David Haller's mind was too damaged, fragile, and broken to allow him to manipulate events and people at such large scale. Charles' son was just a pawn in someone else's game, just like I was about to become.
A much darker and malevolent force was behind the takeover of Muir Island and all its inhabitants, an ancient evil who was planning on using me as the nexus between the real world and the astral plane to bring all things to an end... The Shadow King!