[This is just a sneak peak, not good or detailed as will be in the story. Some elements will be missing, but this is the basic script.]
Both Frisk and UltSans entered the very long hallway of the Ruins. The room hollowing with silence.
Flowey, remaining on UltSans' left shoulder, moved slightly forward and turned to look at Frisk.
Flowey: "Ugh, why are here? There's nothing!"
Then, before anyone could say anything. GG!Underfell Sans flied from behind them, grabbing Flowey with his right hand, and flying away.
After that instant, both Frisk and UltSans stopped, and GG!Underfell Sans stopped in some distance, and turned around to look at them while floating.
Flowey: "Drop me! Put me down!"
GG!Underfell Sans: "What's the matter, you damn parasite? Can't get into something?"
Then, GG!Underfell Sans started compressing Flowey on his hand, and Flowey yelled.
Both Frisk and UltSans hesitated for a second. Frisk sweatted in worry to the new foe they had to go through. But UltSans remained firm, and staryed to close his right hand slowly into a fist with strength.
UltSans' face was half shadowed, but then a small red spark flickered in his left pupil.
The camera view changed into full darkness, and there was nothing, except a white silhouette skeleton with small goat horns, and a red silhouette.
The view then changed to have the skeleton all over the foreground.
Skeleton: "Don't."
Then changed to be the red silhouette now.
Red silhouette: "You."
Then changed again, but were both together and mix while cut, the left half from the camera's view was the skeleton, and the right was the red silhouette.
Both: "Dare."
GG!Underfell Sans hesitated, but he then grinned and started making Flowey suffer, but then, GG!Underfell Sans boosted himself and flied away.
Both hesitated, but suddenly, UltSans started running, quickly reaching GG!Underfell Sans. And in a sudden, UltSans jumped and grabbed GG!Underfell Sans' right leg with his left hand, and crashed him against the ground firmly.
GG!Underfell Sans dropped Flowey, while UltSans started lifting and swinging GG!Underfell Sans around like a bag, crashing him against the ground and walls.
After a short moment, UltSans swong GG!Underfell Sans's right leg up, boosting him to get up, but to grab his skull, and UltSans then started running while making the back of GG!Underfell Sans's skull get crashed against the wall for a moment.
Then, UltSans stopped, and crashed GG!Underfell Sans's skull against the wall over and over, until breaking the wall and cracking the back of GG!Underfell Sans' skull.
UltSans then dropped GG!Underfell Sans' skull, and punched it with his left fist, and then grabbed GG!Underfell Sans' magic eye with his right hand, and with a sudden lift, broke the top and right side of GG!Underfell Sans' skull.
UltSans then punched GG!Underfell Sans' skull again with his left fist, but now it did massive damage, shattering it, and he dusted away.
UltSans remained still, his left fist bleeding, and his right hand holding the magic eye of GG!Underfell Sans and with red and yellow lighting coming from it to be around his right hand.
He hesitated, but then grabbed GG!Underfell Sans' jacket, and turned around to walk towards Frisk who was walking towards him with a worried expression and holding Flowey.
Flowey was shaking of worry for other reasons.
They stopped in front of each other, and UltSans offered the jacket and the magic eye to Frisk.
Frisk hesitated, but then moved Flowey to be again on UltSans' left shoulder, and grabbed the jacket and the magic eye, both items now in Frisk's inventory.
Both hesitated, Flowey still in shock and shaking. But then, after a short moment, they continued their way through, the hallway now ended, and they continued their journey.