Luke died without training anyone, the jedi are dead. The only possible remnant are currently in a different galaxy and none of that lot claim to be a jedi. Ahsoka saw first hand the folly of the jedi dictates that caused anakins fall. Which is why she's training a fully grown adult mandalorin,rather than indoctrinating a child. As is the jedi way.

It was forged into a collar bound, round morgoths neck then thrown through the doors of night into the timeless void with morgoth, thousands of years earlier, so no longer exists in the world is what happened to it, also considering that it was so massive that beren couldnt move it, theres no possibility of any lesser being picking the thing up to stab sauron with, even if it still existed within space and time.