What are some interesting plot ideas for a 'Deltarune meets Undertale' fanfiction?

One idea could be that the characters from Undertale find themselves in the Deltarune world and have to adapt to its different rules and characters. For example, Sans could meet Ralsei and they could have a humorous exchange about the nature of their respective universes.

One idea could be that the characters from Undertale find themselves in the world of Deltarune. For example, Frisk could end up in the Dark World and have to figure out how to get back home while interacting with the Deltarune characters. They might team up with Kris to fight against new threats that are a combination of both universes' villains.

Another plot idea is a story where the antagonists from both games, such as Flowey from Undertale and the King from Deltarune, form an alliance. Their goal could be to take over both universes. This would force the heroes of both games to work together. The fanfic could explore how the different characters with their own powers and personalities interact and strategize to defeat this powerful alliance.

Well, a cool plot for 'Undertale meets Underswap fanfiction' might involve a character exchange program of sorts. Papyrus from Undertale goes to Underswap and tries to teach his Underswap counterpart how to be more confident in his cooking skills. At the same time, the Underswap Sans could come to the normal Undertale world and introduce new ways of having fun to the rather serious Sans there. This could lead to a series of comical and heartwarming interactions between the characters from both universes.

A plot could involve a love story between a character from Undertale and one from Underfell. Their different worlds' values and cultures clash, but they still manage to find common ground and fall in love. This could lead to them trying to bridge the gap between the two universes to be together.

One interesting plot idea could be that characters from Undertale end up in the Overtale universe and have to adapt to its different rules and power systems. For example, Sans might find it strange that magic works in a more complex way in Overtale. Another could be a character from Overtale getting lost in the Undertale world and having to deal with the moral choices that the Undertale characters face, like whether to kill or spare enemies.

Well, in 'mlp meets undertale fanfiction', there could be crossovers of characters. Picture Fluttershy befriending a shy monster in Undertale. Her kind nature could help the monster come out of its shell. Also, the magic system in MLP could blend with the combat or determination - based mechanics in Undertale. It might create new ways for the characters to overcome challenges. For instance, Twilight Sparkle's magic could be used to solve some of the puzzles in the Underground in a different way than the normal Undertale characters would.

Definitely Sans and Jevil. Sans' laid - back yet perceptive nature combined with Jevil's chaotic and unpredictable personality would make for some really interesting exchanges. Sans might try to understand Jevil's view of the world, which is so different from his own in Undertale.

One interesting concept could be the crossover of characters' personalities. For example, how the determination trait from Undertale might interact with the more mysterious elements in Deltarune. Another could be the exploration of different timelines. Since both games have some elements related to time and alternate realities, a fanfic might delve into how these timelines could cross or affect each other. Also, the unique magic systems of both could be combined in creative ways, like how the soul powers in Undertale might work with the magic in Deltarune.

One idea could be a Deltarune and Undertale crossover. You could have the characters from Deltarune end up in the Underground from Undertale. They might interact with Sans and Papyrus, for example. The contrast between the two worlds' rules and the different character personalities would create a lot of interesting scenarios.