Give them real - life emotions. For example, if the OC is shy, show how she blushes when Natsu talks to her. And for Natsu, show his insecurities sometimes, like when he doubts his strength in front of the other harem members. Also, let the characters make mistakes. The OC could accidentally use her magic in the wrong way and cause a small problem, which makes her more human.
Relatable characters often have dreams and goals. The OC could have a goal of becoming a great mage like Natsu. She struggles with her studies and training, just like real people struggle to achieve their dreams. For the harem members, they could have different goals too, like one wants to protect her family with her new - found magic. Natsu can also have relatable traits like his love for food, which is something many people can understand and connect with.
To make your possessive OC more relatable, give them insecurities. Everyone has insecurities, and if your OC is possessive because they're insecure about losing someone or something, readers can understand that. For example, if they've lost a lot in their past, they might be overly possessive of what they have now.
Give them real - life problems. For example, if it's a family dealing with a jaded attitude, show them struggling with things like paying bills, getting along with neighbors, or dealing with a difficult boss at work. This makes them seem more like normal people.
Give them normal human flaws. For example, if a character is a hunter, make them afraid of something really simple like spiders, even though they face big supernatural threats. This makes them seem more real.
Give them common human flaws. For example, if the angel character is always seen as perfect, give it a fear of heights or a small addiction to human food which is considered strange in the angelic world. This makes the angel more relatable.
For Rodrick, show his insecurities more. Underneath his tough exterior, he might be worried about not being good enough, especially compared to his more successful brother. For the reader character, give them normal, everyday problems like trying to fit in at school or dealing with family issues.
Give them normal hobbies outside of music. Maybe one of them likes to draw or play football. It shows that they are not just music - making machines and have other interests like ordinary students.
You can make fictional characters relatable by giving them flaws and vulnerabilities. When they're not perfect, readers can see themselves in them.
For Black Widow, you can focus on her vulnerability. Despite her tough exterior, she has a soft side. Show her missing her past, her family that she lost. For example, have her talk about her memories of growing up in the Red Room. For Scarlet Witch, emphasize her struggle with her powers. She's so powerful but often scared of what she can do. Let her have moments of self - doubt, like when she's trying to control her magic and it gets out of hand.
For Psyche, you can give her relatable flaws. For example, she could be overly curious which often gets her into trouble, like when she peeks at Cupid's face when she's not supposed to. For Cupid, show his vulnerability. Despite being a god of love, he might be insecure about his own ability to be loved back by Psyche.
Develop their backstories well. A character who has overcome a great tragedy in their past is often more interesting. You can gradually reveal bits of their backstory throughout the fanfiction. Physical appearance also matters. Describe their appearance in a way that stands out, like 'her eyes were the color of a stormy sea'. And don't forget about their relationships with other characters. Whether it's a best friend or a rival, these relationships add depth.