You are offered the position of Absolute Dictator of the United States for a period of 10 years. You can implement any changes to the Constitution, fire anyone, disband anything, change any law, even have people arrested and imprisoned or executed. True absolute dictatorial powers to remake the nation in the image you desire over the course of a decade.
But the catch is that you personally will be put to death at the end of the decade no matter what. It's the one thing you cannot change, cannot avoid, cannot alter in any way. Even if you do the best job ever, you will be put to death at the end of your term. So no clever 'I would change the rules so I don't' or 'I would flee to another country right before it's over' or other dodges like that. You absolutely will die after the term is over. You in essence will be performing a soldier's sacrifice, but only much more effective and individually focused. Instead of giving your life for your country in the hopes of saving it in the abstract, you personally will be able to actually save it in whatever form you think that takes, but you will absolutely be giving your life for it.
Do you take the deal?
No because the time limit breeds complacency.
One of the biggest issues we have with term limits at the TOP is that it makes people go 'we can just outlast this and change it back later' so no matter what impact you have, there will always be 'pull back' from those after your reign. Especially if this is a one time deal.
You can have term limits in lower positions but at the very top if the person has THIS much authority, it's best that they can focus on legacy than have to keep watching the clock for their 'term limit'