Frostbite
I... just can't do it by myself. But if you can help me... I have a plan.
Media: Deltarune but as if it had ended after the second chapter, for now. Probably won't change even after the release of the whole game but I'll adapt it if I change the timeline to fit the game's.
Relevant AU info: Kris never opened the Dark Fountain in their house, they just decided to sleep through the night... no, not really. Instead of taking out "their" soul to tear Toriel's wheels, they decided to try and talk to it. Turns out, the soul is actually Frisk and Chara, who ended up in Kris' body after the genocide route in Undertale -in my AUs Demon Chara and Chara aren't the same beings, Demon Chara fooled both of them after it promised to recreate their world-. Kris didn't want to be controlled by them, and they didn't want to control Kris, but they needed a body to persist, so the three of them decided that Kris would host the soul but they would have complete control of everything. That way, the determination could still help Kris in the Dark World, and Chara and Frisk wouldn't disappear. Also, usually in my AUs I always portray the monsters as humans; this time, they are semi monsters.
Plotline: a few weeks after sealing the Cyberworld's Dark Fountain, just a month away frim spring's festival in Hometown, another Dark Fountain appeared. However, no one seemed to find the way to enter that new Dark World, not even Ralsei, so they decided to investigate a bit during the preparations of the festival. During that time, someone, Tyler, moved to Hometown, and the Lightners suspect that he has something to do with the Dark Fountain.
Previous events: after their day in the library, Berdly returned to his house, and his parents asked him about the scars that appeared suddenly in his face. Instead of questioning them, after thinking for a few seconds, he said that he went to the forest with some friends after studying, and face-palmed into some branches that were on the ground; surprisingly, they believed him. He ran to his room and called Noelle. They both were completely sure that everything that they experienced that day wasn't a dream, there was no explanation for the scars they now had in their bodies. The next day Berdly and Noelle asked Kris and Susie about the events of the previous day, confessing that they knew it wasn't a dream. They briefly explained to them that there was something called "Dark Fountains", and that they had to seal them or else the chaos would reign, but they decided to visit Ralsei during their recess so he could explain everything better. From then on, the Lightners' team would have two more members.
Tyler's basic info: he's a raccoon semi monster, and his magic is related to nature and plants. His spells are mainly healing, he also has some attacking spells but he needs a lot of concentration to use them in the Light World, and a lot of TP to use them in the Dark Worlds. His weapon in the Dark Worlds is a spear made of plants. Before moving to Hometown his life wasn't exactly good. He was always the outcast in class, and his parents weren't exactly supportive when it came to his identity and beliefs. He created his own little world inside of his head so he wouldn't feel as lonely and misunderstood. After meeting the gang, that imaginary world started to disappear as he found true friends... or did it?
Toy Kingdom: a Dark World created by Tyler's imagination. The only way to enter it is through the closet in Tyler's room. It existed for a very long time, but only after moving to Hometown it took a physical form. Tyler has no idea it exists, but suspects about it existence after visiting Ralsei for the first time after he heard his friends talking about the Dark Worlds -it had no use to hide it since they were going to tell everyone eventually-. Plushies, puzzles, toys, every kid's possession to imagine is alive in the Toy Kingdom. At first there were only Tyler's toys, but more things started to appear: Noelle's dolls, Susie's toy guitar, and even the red horns Kris owned.
Spring festival: the school prepares a festival every year during spring break. The students prepare booths going from the school to the square. These booths range from small games to food and drinks. The gang was planning on telling everyone about the existence of the Dark Worlds, that way Ralsei, Lancer and the rest could enjoy the festival as well. The festival begins around 7pm, and ends at 12pm with some fireworks and mini disco near the fountain.