I was inspired by anime_sonicmega's "Papyrus Genocide [AU]" voice work and used a few of my favorite lines in Papyrus' dialog.

I don't own Undertale

The door to the ruins stands open behind you, what lay behind now deathly silent. Toriel's dust still clings to you. You contemplate what comes next as you walk down the long hall, your soft footsteps echoing. The battles that are to come, who will fight and who will flee, you've done this before. They'll fall so easily to your knife; all except one. Sans hadn't been able to stop you in the end, but he had proven himself to be a significant obstacle. But now the world was new again. It was time to experiment, there had to be a better way.

Besides you had all the time to kill.

Your fingers itched to hold a knife, but you smile when Sans greets you. He's wary of course, he always is, but it's ridiculously easy to befriend the skeleton brothers. You humor Papyrus, play his puzzles; Sans begins to relax. Still, you slip a few times. Snowdrake falls before you in dust; the last joke was on him. You silence the whimpering of the dogs, they could smell the dust of your hands. Still, you proceed to the end and when Papyrus blocks your path you spare him with a smile and he calls you friend.

It has to be now, while Sans' guard is down, before he can grow suspicious and troublesome once more. You meet him at the door of the half empty Grillby's and slide the knife in. That horrible blue eye lights up, but you don't stop till there is nothing but an empty coat and dust on the snow. So much easier this way, all it cost you was some patience. Smiling, you empty Snowdin…

*but nobody came.

Frustratingly, you don't find Papyrus. Yet there have always been those that have escaped your blade, like the coward Alphys. How sad not be able to reunite the brothers in death, but it is a loss you are willing to accept to forgo that tedious battle.

As before, they fall again, Undyne the Undying, Mettaton NEO, all those they fail to protect, all fall to dust. Until you stand in the empty golden hall once more. No one can stop you, it's almost too easy. You see a familiar silhouette wearing a familiar jacket, but the jacket's new owner is much taller than his brother.

Papyrus blocks your way.

"HUMAN… I ONCE CALLED YOU MORE THAN THAT, DIDN'T I?

NYEH HEH HEH HEH HEH…

AFTER YOU TOOK MY BROTHER AWAY FROM ME… I FINALLY TOOK A LOOK IN HIS WORKSHOP. DO YOU KNOW WHAT I SAW THERE, HUMAN?"

Papyrus' eye glows with a horrible orange light; as he speaks you feel your sins crawling on your back.

"ALL THE THINGS YOU HAVE DONE. ALL THE THINGS YOU MIGHT DO. SANS KNEW WHAT YOU WERE. I SEE NOW, WITH THIS EYE OF MINE.

I TRIED SO HARDTO BELIEVE IN YOU, TO CALL YOU MY FRIEND…

I CARE ABOUT SO MANY THINGS IN THIS WORLD. WHAT I NO LONGER CARE ABOUT…

IS YOU."

Papyrus no longer believes in you.

"I'M NOT GOING TO GIVE YOU A BAD TIME, HUMAN. NO, SOMEONE LIKE YOU DOESN'T DESERVE TO BE GIVEN ANYTHING.

INSTEAD I WILL BE YOUR EQUAL AND FACE YOU WITH AS MUCH DETERMINATION AS YOU HAVE AND PROTECT WHAT YOU HAVE COME TO DESTROY.

SO, HUMAN…

YOU ARE NOT GOING TO HAVE A BAD TIME. INSTEAD…

…I'M GOING TO HAVE LOTS OF FUN."

Papyrus prepares a non-bone attack.

As the gaster blasters' beams tear through you, you realize you made a terrible mistake. Papyrus had always fallen so easily to your knife; you cut him down so many times as he stood offering mercy.

Papyrus prepares a bone attack; you're blue now.

His attacks had once been slow and patient; it dawns on you that he truly had never intended to hurt you before. Those slow bones had been a game, like the puzzles he had presented to you before. He'd been holding back.

Papyrus' attacks with blinding speed, his bones shattering you mercilessly.

You remember what you had read in the library, what seemed like a lifetime ago; the nature of monster magic and their SOULS. Sans, despite all his strength and all his power, was a lazy bones by nature. Papyrus, however, had always been filled with relentless stubborn energy that he had used to create puzzles and cook spaghetti and acquire friendship.

Now, filled with the determination to kill you, Papyrus crafts his attacks with that same energy. Elaborate patterns of bones fill the arena, very cool gaster blasters circle you, and you realize…

you're about to have a very bad time.

As you pull yourself together and step into the golden hall once more, you recall Sans would have begun tiring by that point in the battle, he would have started cheating. Papyrus wouldn't stoop to such tactics, he hasn't needed to. He's also showing no such signs of weariness.

"NYEH HEH HEH!

HOW MANY TIMES IS IT NOW, HUMAN?

LETS TRY SOMETHING DIFFERENT THIS TIME. I WOULDN'T WANT YOU GETTING BORED.

NOT WHEN I'M HAVING SO MUCH FUN!"

Your determination begins to waver…

Papyrus is having a great time.