Mafia 27. The problem of Bovblob residents

1. If the Hatter steals a Night Defense (ND) from a player who isn't using their ND on the current night, will the theft be successful, and will he be able to use it? For clarity:
The Ringmaster doesn't take any action on the second night, and the Hatter steals his ND. Will he be able to kill on the third night, using the stolen ND, even though it won't work, or will the theft be unsuccessful?

2. Let's say the Hatter steals ND from a Unicorn on the second night. The Unicorn is killed, and the remaining Unicorn, the victim of the theft, is left without any ND at all. What will happen to the stolen ND? Will the Hatter consider the theft successful, and will there be no information about its failure? Will he be able to use the stolen ND, or will the ND also be nullified for the Hatter?