Gary, an avid anime fan

Finding the Rulebook and reading it, he decides to test it first. A man at another table had on a blue shirt and was talking to a woman, probably his wife or girlfriend, and Gary thought of a simple change.

Old rule: The man Gary looked at last before writing this rule has on a red shirt.

When he next looks up, the man's shirt is red, and no one noticed! Unless this thing has a limit, he can do anything!