We saw through the preview that Proteus has started his garden and his seeds are planted all over the world. Psylocke is in command and has a plan. The Xmen put it to use. It mainly consists of OML. Archangel and Mystique using metal and morphing into his mother. Once they drain him, Rogue and Bishop convert his energy and release him back to the universe so to speak.
Whilst this all went down Psylocke and X combined forces to burn out the seeds across the planet. As they are working on it they discover they are not enough to accomplish the task. X mentions the network of psychics the Shadow King was using and that Betsy who is in control should tap into it. She agrees and does so. As soon as she does X says oh yes my pretty and transforms into the Shadow King.
Honestly predictable and boring. Art was good. I enjoyed the blend of coloring and effects used but story fell real flat. Proteus' end was very anti climatic and the reveal was seen coming in like issue 3. I can see why a reboot is coming.