A single animation AU which takes place at the end of a genocide run where there appear to be no survivors. Grillby and Alphys appear with the other characters despite never having being killed by the player in classic Undertale.
Despite the creator (Animated Zorox) maintaining ownership of the AU, they have no intention of continuing the AU themselves. According to the description of the animation, the creator intends for others to continue the series instead (which means free reign over Delta!Sans). They want it to become a community-driven AU.
During the fight, Chara absorbs Frisk's soul and kills Sans. As Sans is dying, Asgore and Flowey arrive with the orange soul. They are killed but their distraction allows Sans to absorb the orange soul, becoming filled with Bravery.
Souls appear with human soul surrounding the monster's soul (Similar to the Dreemurr Reborn soul which the UTAUWiki uses as it's logo). Unlike Reborn, however, the monster soul maintains it's orientation (i.e. upside down).
Watch the animation here before reading on as the characters section contains spoilers. It's only 8 1/2 minutes long.
This version of Sans is called Delta!Sans, he appears similar to Classic but has lost his jacket, has gained black streaks that run down from his eyes, a Gaster Blaster on his back and spiked orange gauntlets with black hearts on the back of Sans' hands. When taking combat seriously, his eyes glow orange. Delta!Sans becomes a timeline jumper at the end of the animation, wanting to prevent similar genocides.
They do seem to be more forgiving than Classic though, as they forgive Frisk despite Chara only gaining control at the end of the genocide (this may just be a plot hole though). They are also now sharing their body with the Bravery soul. When talking to Bravery, Soul to soul, he appears as Classic. Time freezes when they speak to each other.
Omega!Chara is present in this world and looks similar to Classic Frisk/Chara but has the color and patterning of the Real Knife (Red with rings in a lighter red). Their eyes appear sideways like Photoshop Flowey's. Chara is genuinely evil in this AU and is killed at the end of the animation.
All other characters in this AU seem to be the same as their classic counterparts.
- Chara can absorb Frisk's soul because they are a ghost and ghosts are considered to be monsters (Napstablook).
- Frisk loses the ability to reset when they are absorbed.
- This AU is open to others to build on, this is basically an origin story for Delta!Sans.