How about Fiendfyre? Does that leave anything behind? I mean, it cut through Hogwarts.
I can’t answer that question (though my instinct is to say “no”), but I will point out that Hogwarts isn’t particularly indestructible. Haven’t we at least seen one of the trolls damage the walls with ordinary brute force? Or am I misremembering?
The troll grasped its fallen club in its remaining hand, and gave a huge bellow, smashing the club into the floor and sending marble chips flying.
Also
In one narrow circle the marble tiles were scorched and shattered by some explosive spell that only the most prodigious of first-year witches could have cast, with the last of her strength.
I can’t answer that question (though my instinct is to say “no”), but I will point out that Hogwarts isn’t particularly indestructible. Haven’t we at least seen one of the trolls damage the walls with ordinary brute force? Or am I misremembering?
We did see that:
Also