Cruel Twist Ending/Playing With

Basic Trope: A twist ending occurs that seems to have the sole reason of being very cruel.

Straight: As Bob finishes his journey and prepares to become ruler of the kingdom, it turns out he's dying of cancer, and then the series ends.
Exaggerated: Right before Bob becomes king in his merry land, it is revealed out of nowhere that the universe is ending. This is how the series ends.
Downplayed: As Bob finishes his journey and prepares to become ruler of the kingdom, it turns out that he's ineligible for the post, and the series ends.
Justified: Bob has managed to upset some sort of cosmic entity during his adventures, leading to sudden horrible events just as he nearly tastes victory.
Inverted: Bob spends the whole series suffering, but right before the ending it turns out that he has been blessed by the gods, and he is suddenly showered in happiness.
Subverted: Bob, about to have all his goals in life fulfilled, turns out to be dying of cancer, until he wakes up and realizes that he dreamed the cancer part.
Double Subverted: ...Except that when he wakes up, he goes to the doctor and finds out that he has cancer anyway.
Parodied: During his Awesome Moment of Crowning, the Anthropomorphic Personification of the Cruel Twist Ending crashes the ceremony and explains he can't allow Bob (or anyone else, for that matter) to actually have a Happy Ending. So it has the kingdom turn into Mordor, replaces Bob's Love Interest with a camel, and kicks his dog for good measure.
Deconstructed: The sudden, jarring doom from left field turns Bob into a bitter and angry man. Knowing he has only a scant few years to live, he sets in motion events to Rage Against the Heavens and slay / replace / create the entity that can properly enforce Karma. And if that fails, he'll bring the universe down with him by becoming the Fisher King and letting his cancer kill both himself and the kingdom. No more sad endings after that, all just to spite the uncaring narrator.
Reconstructed: Except Bob realizes life isn't supposed to be fair, a fair universe is exclusive to fictional characters created by authors who want them to be happy. And he isn't a fictional character... right?
Zig Zagged: Right before the book ends, it turns out that Bob has cancer. Wait, no he doesn't... it's his twin brother, Carl, who was mistaken for him. Except Bob's been dreaming all this, so he wakes up to victory. Then Alice, the princess he was about to marry, suddenly dies. Or did she?
Averted: Bob's story ends without any cruel twist.
Enforced: "We need our series to be different. Hmm. Every other TV series has happy endings, so let's spend ours yanking the poor dog around before running it over!"
Lampshaded: "What? That's just... cruel."
Invoked: The villain decides to withold a certain piece of information from the hero and let him nearly win, just so that the crippling detail can be revealed right before the hero might win.
Defied: Bob decides to live as happily as he can despite the cancer, help as many of his subjects as possible, and be content to have accomplished something great before dying. In that way, whatever evil "author" might be orchestrating his misfortune is denied satisfaction.
Discussed: "What's up with that? Just as everything's finishing up... I didn't even have any reason to expect that... Are the gods mad at me or something?"
Conversed: "What? What kind of last episode was that? Was there any point to that twist besides being mean to the characters?"

"And so, the tropers decided to go back to Cruel Twist Ending... except now they have no hands to hit 'Back'! And became blind! And, and and... wait, you can't read this now can you? Drat. No point narrating / gloating anymore is there? Geez, being a Jerkass Narrator is harder than I thought."