So, would you prefer something that allows governments to manipulate bitcoin but can't control it (decentralized currency after all) but that would help you too, or would you want government to be out of it all together even if that means it would hurt you? I am not entirely sure but the reason why bitcoin was created was a bit of resistance towards current system so I would say latter would be better.
If you are a big nation, just tell the world that you are considering banning bitcoin all together, and even have a public announcement that you want to meet other big world leaders on potentially banning or at least limiting very much with full government knowledge (like KYC but harsher) to even own bitcoins, that will drop the price a lot. Buy as many bitcoins as you can as government when the price is that low and continue to be harsh.
After a while when you have enough, tell everyone you changed your minds and you will allow bitcoiners to exist and also will support them, that will increase the price a lot. You can sell after this stage.