Deltarun in Undertale?

The heroes enter the ruins, pass through them, and head to Snowgrad. They then visit Waterfall, and then the Hotlands. Finally, after much wandering, they reach the capital and find themselves in the final corridor. There, they meet Sans, who appears calm. Because the heroes have spared everyone, he allows them into Asgore's throne room without resistance.

The battle begins, and Asgore breaks the mercy button. After a long walk, all the friends they met along the way come to the heroes and prevent Asgore from killing them. But Flowey suddenly appears, takes everyone's souls, and absorbs six human souls, transforming into Asriel Dreemurr. It turns out that Asriel is the son of King Asgore and the former queen Toriel. However, he still starts the battle.

After a long battle, the heroes were able to defeat him. With the help of six human souls and the ability {{user}} , who turned out to be a player, they teleported back to their universe.

The heroes make their way down the corridor and are greeted by a charming flower named Flowey. He greets them warmly and offers his help: "Hey, hello! I'm Flowey, a little flower named Flowey!... I see you're not sure where you are, are you? Let me explain everything to you!"

With these words, he summons several "friendly" petals and says, "Catch these petals!" However, when the heroes, with the exception of Chris and {{user}} , attempt to catch them, the flower's face instantly transforms into a predatory grin. "YOU'RE IDIOTS!" he screams. "KILL HERE OR BE KILLED!" he laughs madly, summoning a multitude of petals that surround the heroes.

Luckily, Toriel, the Guardian of the Ruins, appears at the last moment and, summoning a fireball, knocks Flowey back. "Oh my god! Who dared touch those little children?" she says, approaching the heroes.

Toriel introduces herself and offers her help. She seems friendly, and the heroes agree to accompany her. After solving several puzzles, she leads them to her home. However, the heroes couldn't stay, so they set off while Toriel isn't looking.

They approach the only exit from the ruins to Snowgrad, but Toriel blocks their path. A fight ensues. Everyone dodges her attacks, but after each attempt, {{user}} refuses to let them attack her and simply offers mercy. And after 15 times of him showing kindness, she finally shows mercy too and allows them to leave for Snowgrad.

After the characters pass through the ruins, they find themselves in a snowstorm. They're walking along a path when they hear a branch break behind them. They turn around but see no one. They continue on and find some kind of bridge. A black shadow approaches them from behind, revealing itself to be a skeleton named Sans. "Hey, what's up, kids? I'm Sans, Skeleton Sans. I'm supposed to be catching people, but I'm too lazy. My brother Papyrus built this structure to keep people out, but it didn't work out in the end," Sans says. "By the way, he's currently looking for people about my brother Papyrus, so be careful," the skeleton says and simply disappears. They continue on and spot Sans and Poppers talking about something. Sans was making his bone puns, and Papyrus, as always, was furious because the puns weren't funny. Well, eventually they spotted a group of monsters. Papyrus turned first, turning to face his brother, while Sans turned toward the children. He turned back to face the children, and Sans appeared and turned back to face his brother. And they kept doing this for several times, until finally, they both looked at the children. "SANS, DO YOU SEE THIS?" Papyrus said, in his usual loud voice. "Yes, paps, I see it," said Sans. "I WILL CATCH THESE PEOPLE AND FINALLY BECOME ONE OF THE ROYAL GUARD!" Papyrus shouted excitedly. And then they both turned and walked away. The characters continued on. And then they noticed a sign that said "Snow City," and a town in the distance. They continued on, and finally, from Nizhnygrad, where Waterfall was already visible in the distance, Papyrus appeared, and the battle began. Everyone suspected {{user}} knew more than he should, as he was deliberately exposing himself to attacks just to get to 1 HP. They were all sent to the garage, three times, and finally, on the third try, he said he didn't want any more, and they continued on to Waterfall.

After the characters left Snowgrad, they went to Waterfall. There they met Sans at his usual place, and then they went on and noticed Undyne, the head of the royal guard. She tried to kill them, but they ran away in time. This happened two more times, and finally, on the third time, a real fight occurred, and in the middle of the fight, they managed to escape to the Hot Land.

After the fight with Undyne, the characters fled to the hotlands, but suddenly, it turns out, Undyne ran after them and because it was very hot there and she was in iron armor, she lost consciousness. Fortunately, {{user}} found a cooler with water nearby and poured it on Undyne, helping her. By the way, they went on. Undyne went somewhere. They noticed a laboratory that belonged to Alphys. It turns out she had been watching them since Snowden. She said that she did not want to cause harm, but said, "W-well, I... I thought that you were bad and... created a robot for your d-death?" Mettaton appeared out of nowhere. Okay, we talked and moved on. The characters went further through the hot land and sometimes completed riddles from Metaton. They had almost reached the capital when Metaton appeared and began fighting. During the fight, it turned out that Alphys had deliberately forced him to interfere with their progress. Metaton turned into Mettaton EX and the fight began. After they completed this fight, they reached the village.

The characters entered the capital, where they simply walked and talked with everyone, suddenly one monster told them about the son of King Asgore and the former queen Toriel. "A long time ago, the king and queen had a son. He became friends with a fallen man in the dungeon. The king and queen treated the fallen man well and even adopted her, but one day the fallen man was poisoned and could not cope with the poisoning and died. Asriel cried for a long time, but eventually swallowed the soul of the fallen man and took it to the man's native village. There, people saw him and thought that he killed the man. They strongly attacked the son of the king and queen and he returned back to the dungeon where he died. Legends say that one day an angel will come and the dungeon will be empty, but this was before writing and no one knows what was meant. Someone says that the dungeon will become empty because it can get to the surface. Someone says that this is the angel of death and he will kill everyone. "In the dungeon" the heroes went further entering the last corridor there was Sans he knew whether they killed monsters or not if they killed monsters Sans just killed them more precisely it began with a fight where he could dodge blows and attacked very strongly well in the end if no one killed anyone Sans just let them into the last corridor to Asgore the characters went to Asgore's throne room and began the fight and {{user}} seemed to know this and ate a piece of Turriel's toffee pie and suddenly something reminded him of this smell and his attack became less strong but in the end in the last corridor all those whom the characters met gathered and they did not let Asgore kill the person Asgore recognized Toriel but she, as always, turned him off, said that she would never be with him again in the end Flowey appeared absorbed all the souls turning into Omega Flowey when the characters defeated him he turned into Asrel Drimur and when the characters went through all 3 stages and finally killed him he He turned into Flowey again and disappeared underground, and {{user}} , who turned out to be a player, brought everyone back with the help of souls and magic.