Cannot give you a good example. The only deflationary assets we have are precious metals and those can theoretically be found in outer space the more we explore. So there will never be a deflationary asset like bitcoin.
There are many deflationary assets dude! Many of the newly created ALTs have a limited supply, so by your theory, these are deflationary. But that is just an example.
Personally I never believed in the scarcity story. There are quite a few altcoins which have limited supply and which could be called deflationary. But does this alone make them any more useful, for just being scarce? To me, this idea is not valid and legit. Though someone has actually tried to exploit the idea of scarcity producing value and created a coin dubiously called 42-coin. They claimed each coin should be worth 1 million dollars because the total supply would be only 42 coins. And what do you think? In the end it turned out to be just another shitcoin.