Repentance seems to be very rare among the powerful.
I tried to search with multiple LLMs and in other ways for examples where a king or a dictator realized the evilness of some of their past actions, realized their rule is not justified, and voluntarily resigned. I have not found a single example of this happening.
There are some examples of kings and dictators voluntarily resigning, but it's usually motivated by being tired of ruling (often for health reasons), and very occasionally genuine support for democracy. But as far as I can tell, it's never because a ruler realized the evil of their ways.
I also searched for crime bosses, warlords and successful large-scale fraudsters who voluntarily gave up their evil ways due to repentance. Again, there were hardly any examples. People sometimes repent in prison; people sometimes turn themselves in to the police when they see they will soon get caught anyway; and people sometimes retire from crime to a safer life-style, keeping their ill-gotten gains to themselves.
I only found two examples of successful criminals changing their ways while still successful due to a change of heart - Nicky Cruz who was a gang leader in New York, and General Butt Naked, a Liberian warlord. And even there, I'm a bit suspicious - many of General Butt Naked's stories of his previous horrific atrocities seem false, and I wonder what else is false in his story.
I'm interested if people can find better examples of evil leaders and successful criminals repenting while still in power, I would be relieved to see more examples of this happening.
I find the rarity of repentance of the powerful a very sad fact about human nature, and it makes me less optimistic that current dictators and unscrupulous politicians will significantly change for the better if given superintelligent AI advisors. Of course, one can still be an okay or even maybe a good ruler without ever repenting their evil actions in the past, but I still don't feel great about thi