However, this was a very cruel deception. There was no hope that Anne would be spared her death sentence and enter a nunnery instead. It is unclear whether or not Thomas Cranmer knowingly lied to Anne, knowing she would agree to it and be of good cheer. It is also possible that Cranmer was being misled by Cromwell and the King and had no idea that such a suggestion was a lie. In either case, Anne would have no chance to go to a nunnery and avoid her execution. The only mercy she would receive was a quick end to her life.
There is no evidence that King Henry VIII took any delight in signing Anne's death warrant - in fact, he seemed to simply want to get it over with, and he was moved by pity to commute her sentence to beheading by a French swordsman (which would apparently be quick and painless).