There are fanfictions where Gaster is reunited with the other characters in unexpected ways. For example, a story could have him reappear during a crucial moment in the Underground's history and use his knowledge to change the fate of everyone. It could be really exciting as it might bring new plot twists and character developments.
The war between Gaster and Grillby in the fanfiction might have been sparked by a personal grudge or a competition for influence. Maybe there was a hidden secret that drove them apart and into conflict.
You can start by looking on popular fanfiction websites such as Archive of Our Own. Just search for 'Undertale Gaster' and you'll get a list of related fanfictions. Sort them by popularity or rating to find the ones that are well - liked.
Obviously, Gaster himself is likely to be a main character. His mysterious nature makes him a central focus as readers are eager to learn more about him. Another potential main character could be Frisk. Their ability to reset and influence the game's world could be very interesting when combined with Gaster's enigma. They could either be allies or have some sort of conflict due to their different understandings of the world.
The concept of power dynamics is also fascinating. In a 'Undertale Gaster Crossover Fanfiction', Gaster's power, which is not fully understood in the original game, could be compared or combined with the powers of other characters. This might result in epic battles or the need for characters to cooperate in ways they never had to before in their respective stories.
You can try some popular fanfiction websites like Archive of Our Own (AO3). It has a large collection of Undertale fanfictions, and you might be able to find Gaster x Asgore yaoi ones by using the search function.
There might be a fanfiction where Gaster, with his mysterious past and knowledge, helps Asgore deal with the guilt of past actions. As they spend time together, they discover new sides of each other and a yaoi - themed relationship blossoms. It could involve Gaster showing Asgore different perspectives on leadership and forgiveness.
One common theme could be the exploration of their relationship in the context of the outertale universe. It might involve how they interact with the unique settings and other characters in that AU.
There could be some. You might want to check out fanfiction websites like Archive of Our Own. However, the availability and quality can vary. Sometimes it takes some searching through different tags and filters to find the really good ones.
A 'gaster lemon fanfic' is probably a piece of fan - made literature. Gaster is often a mysterious character in certain fandoms. In this fanfic, the 'lemon' aspect might imply a more saucy or exciting narrative. It could be that the author is exploring Gaster's character in a more adult - oriented way, but it could also be a more innocent, yet still 'lemony' in the sense of being a bit edgy or different, exploration of his relationships with other characters, perhaps delving into uncharted areas of his fictional existence.