I am so damn tired of the "Shadow joining G.U.N. makes no sense" narrative. It’s genuinely exhausting because it completely misses the point of his entire character arc. It actually makes total sense and is the peak of his redemption.
He literally takes control of the very institution that tried to ruin his life. He’s not some obedient little lapdog for them; he’s in there making sure they actually do the right thing so they can never pull an ARK-level atrocity ever again.