For instance if utilitarianism is the best theory, then the reverse, maximizing suffering, should be the worst possible. A person following that might seem to do good things, but is secretly bringing about catastrophe.
Has anyone written anything like that? Such a perspective might be good for comparisons.
Other examples would be "Vice Ethics" and doing only things that you could not will to be universal laws.
People following these would probably end up in jail or dead before doing much damage.