One idea could be creating an OC that has a unique bond with a Digimon not often seen in the series. For example, an OC who forms a partnership with a Vaccine - type Digimon but has an ability that is more associated with Virus - type Digimon. This could lead to interesting plotlines about acceptance and breaking stereotypes within the Digital World.
Another interesting idea is to have an OC from the real world who gets trapped in the Digital World during a time of great chaos, like when there's a power struggle between different Digimon factions. The OC could use their wits and knowledge from the human world to try and restore balance, while also learning about themselves and growing stronger with their Digimon partner.
Chapter 725, "Still Want to be the Second Young Master of the Jiang Family!", is the clearest early answer because it turns Jiang Cheng's situation into a concrete plot event.
Look to Chapter 22 for the clearest answer. It begins with Hearing this, Su Yinwan looked at Shang Shaojing with a face full of..., keeps building through Shang, but it's not necessary;
Chapter 629, "The Family is Going to be Gone", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Even after training under Jiang Li for so long, they couldn't...
Chapter 598, "She Blew Up Your Family's Lake!", is the clearest early answer because it turns Gu's situation into a concrete plot event.
Chapter 12 is the strongest chapter-level answer because it starts from Qin?" Jiang Li called out twice, and only then did Mrs. and follows through on The glass shattered on the floor with a crash, attracting the attention of....
Chapter 747, "How did Jiang Dapusa come to this?", is the clearest early answer because it turns Jiang Dapusa's situation into a concrete plot event. The chapter gives readers a real answer by opening on Shu Yan's face was already streaked with tears, yet her eyes remained...
Chapter 860, "Is your friend feeling unwell?", is the clearest early answer because it turns Miss Jiang's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Beside him, Chang Song: "...." At least talk behind people's backs.
The best chapter pointer here is Chapter 4, "She Can Actually Tell Fortunes?!". It opens with Qiao regretted her words as soon as they left her mouth. and closes on A little girl acting mysterious, learning fortune-telling, what is this....
Chapter 869, "This Marriage Must Not Happen!", is the clearest early answer because a shaky connection becomes usable in the plot.