Birdperson is another good choice. His stoic and yet loyal nature can be a great contrast to Summer and Morty. He could offer them some wise advice or even join them in a battle against an enemy from his past.
Jerry can also be interesting. His insecurities and bumbling nature can provide some comical relief. Maybe he tries to tag along on one of Summer and Morty's adventures and just ends up getting in the way most of the time.
Rick is a great character to include. His crazy inventions and unpredictable nature can add a lot of chaos and excitement to the story. For example, he could accidentally send Summer and Morty on a wild adventure while trying to fix the toaster.
The 'Rick and Morty' universe is so wild and full of possibilities. Fanfiction allows writers to explore different scenarios for Summer and Morty that might not be shown in the actual show. For example, they could be in a situation where they have to save the entire multiverse, which would be a great adventure to read about. It also gives a chance to develop their characters further and see how their relationship might change in various circumstances.
Rick is an obvious choice. His intelligence and knowledge of the multiverse can add a lot of depth to the time travel story. He could be the one helping Morty fix the problems caused by time travel, or he could be the cause of the problems in the first place. Another interesting character is Summer. She could get involved in Morty's time travel adventures, and her different perspective as Morty's sister can bring new elements to the story. Maybe she's jealous of Morty's time - traveling and tries to tag along.
A fanfiction could focus on Summer from Rick and Morty meeting Naruto. Summer might be intrigued by Naruto's world and his powers. They could go on an adventure where Summer tries to learn some ninja techniques from Naruto, and Naruto learns about the advanced technology in Rick and Morty's world.
One popular 'Rick and Morty Summer x Morty fanfiction' story might involve Summer and Morty going on an adventure together without Rick. They could explore a new planet and have to rely on each other's skills to survive. Maybe Summer uses her street - smart knowledge while Morty uses his scientific knowledge he's learned from Rick.
One idea could be Summer going on an adventure with Rick to a parallel dimension where all the rules of time are reversed. She could struggle to adapt at first but then use her wits to survive. Another could be Summer getting involved in one of Rick's crazy experiments that accidentally gives her a unique superpower. She then has to figure out how to control it while dealing with the chaos it causes in the family.
It could be some alien she met during one of Rick's adventures. Maybe she got involved with a being from a different dimension who had a human - like form and they had a brief encounter that led to the pregnancy.
In Morty x Summer lemon fanfiction, the emotional turmoil is a big element. They have to deal with their feelings for each other while also considering the implications of their relationship. The setting also plays a role. Sometimes they are in the familiar Rick and Morty universe, but other times the story might take them to new and different places which affects their relationship.
A Morty and Summer lemon fanfiction might revolve around them dealing with an alien invasion in their hometown. They could be the only ones who know how to stop it, so they combine their unique skills. Morty's scientific knowledge from Rick and Summer's street - smart attitude help them outwit the aliens and save the day.
Well, in this fanfiction, Summer could convince Rick to take her to Naruto's world. Once there, they could participate in the Ninja Academy's summer training. Summer might struggle with the physical demands but would be fascinated by the ninjutsu. Naruto, on the other hand, would be curious about their advanced gadgets. It could be a story of cultural exchange between two very different worlds.
One idea could be a time - traveling adventure where Summer and Morty end up in a parallel dimension where their roles are reversed. Morty is the confident, popular one and Summer is the nervous sidekick for a change.