Well, perhaps the single mom OC is working at a place that is somehow related to the world Shadow is from. For example, she might be a scientist researching something that has ties to Shadow's origin. They meet there and Shadow is drawn to her because she's different from the others. She's strong in her own way, taking care of her child and also being dedicated to her work. Their relationship could develop as they face challenges together in the research world.
Perhaps the single mom has lost someone dear to her and Thanatos, being associated with death, has a connection to that loss. He is drawn to her grief and her love for her family. He tries to comfort her in his own way, and as they interact more, a relationship forms. They might go on adventures together where Thanatos shows her different aspects of the afterlife, which helps her come to terms with her loss and also fall for him.
One plot idea could be that Ryan and Dylan get separated during a dangerous encounter in the quarry. They then have to find their way back to each other while facing various threats. This would build tension and also show their determination to be together.
Well, a plot could revolve around Shadow protecting Chris from a group of villains who are after Chris for some special ability he has. It could show how their relationship grows from a protector - protectee one to a true friendship. And then they might face a final big battle together against the main villain.
One idea could be that Cloud and Leon are from different dimensions. They meet by some strange magic accident. Cloud is on a journey to find his lost memories, and Leon, being a more experienced fighter in his world, helps him understand the true nature of his past. They bond over their shared experiences of fighting powerful foes.
One idea could be that the OC is a healer who stumbles upon Frankenstein's monster in the woods. The OC decides to help the monster, despite the danger, and they form an unlikely bond. This could lead to a story of redemption for the monster and a journey of self - discovery for the OC.
Maybe the OC is a scientist who has developed a device that can temporarily steal The Flash's speed. At first, the OC uses it for personal gain, but then realizes the chaos it's causing in the city. They then team up with The Flash to take down other villains who are after the device. Or, the OC could be a meta - human with the ability to see the future in flashes. The Flash initially doesn't trust the OC, but as they start to have the same visions, they have to work together to prevent a major disaster from happening.
The OC could be a psychic who is unknowingly drawn to Derry because of Pennywise's presence. Their psychic powers allow them to sense Pennywise's energy but not fully understand what it is at first. As Pennywise tries to manipulate the OC, the OC starts to fight back using their psychic abilities, creating a battle of wills and powers that could span across different dimensions within Derry, from the sewers to the abandoned houses and the mindscapes of both characters.
The OC could be a researcher studying digimon behavior. Renamon becomes the subject of the study. At first, Renamon is very guarded around the OC. However, as the OC shows genuine respect for Renamon and her kind, Renamon begins to open up. They then embark on a journey to discover more about the history of digimon, with their relationship growing stronger along the way.
Well, an interesting plot could involve an OC that is a transfer student, just like the protagonist. But this OC has a hidden past related to the Metaverse. Maybe they were experimented on by a shadowy organization in their home country, and this gives them a different perspective on the Metaverse compared to the Phantom Thieves. Their goal could be to find out who was behind those experiments and get revenge. Along the way, they form a bond with the group and learn new ways of using their powers.
One idea could be that the OC is a new Keyblade wielder who meets Ventus during his training. They start as rivals, constantly competing in battles and challenges. But as they face a powerful enemy together, they realize their combined strength and start to develop feelings for each other.