Shadow the Hedgehog has always been fairly distanced with even those he was closest to. Considering this, and the fact that chaos energy changes based on emotions, it's no surprise when Shadow loses all control of his Chaos. When he tells Rouge, she tips him off that he may be needing someone to help "tame" his chaos. What is the most surprising though, is the fact that he actually listened to her. #1 in Sonadow at one point