Lilybug4mlp I added more to the idea-
The Stoat stuck around as a representation of his past actions. Greedy, gloating, careless, and always seen as evil. However, it becomes more of a problem than they thought. P03 finds himself going into the stoat form, despite not feeling bitter. After that, his behavior becomes more that of his past self, emphasis on greedy and careless. They find that the stoat had been eating away at P03's files, with 1/4 of them being corrupted when they discover it. Most of the visible changes were caused by the first files to bee corrupted. They need to find a positive side to the stoat, and P03. Before things change for the worst.