Well, you can develop their relationship by creating moments of vulnerability. Maybe the OC has a fear of heights, and on a mission on a tall tower, Lucy helps him overcome it. This creates a bond of trust. Also, have them exchange personal stories. The OC could tell Lucy about his past, his family, or how he came to be at Fairy Tail. In return, Lucy shares her dreams and her experiences with her celestial spirits. This deepens their understanding of each other. Additionally, introduce some jealousy elements. For instance, if another character shows interest in Lucy, the OC realizes his feelings for her are more than just friendship.
To develop their relationship, start with small interactions. Have the OC offer to help Lucy with her celestial spirit summoning, like finding a rare ingredient for a spirit - summoning spell. Then, they could have some shared experiences, such as getting trapped in a cave during a mission. This forces them to rely on each other, talk, and get to know one another better. Another way is to give them common goals. For example, they both want to defeat a certain dark mage who has been causing trouble in the area. Working towards this goal together will bring them closer.
Chapter 795, "Trouble Befalls the Third Lady!", is the clearest early answer because it turns Lao San's situation into a concrete plot event. It opens with The group photo was spreading like wildfire on Weibo. and closes on Jiang Yan dumped all the bottles he'd taken out into the arms of the....
Chapter 817, "Killed by Me", is the clearest early answer because the violence around Meng Wanzhi becomes final instead of hypothetical. The chapter turns that into something concrete by moving from Jiang Buchen leaned against Meng Wanzhi's chest and thoughtfully...
Chapter 435, "A Skilled Housewife Can't Cook Without Rice", is the clearest early answer because the violence around Pei Ye becomes final instead of hypothetical. It opens with The elderly dean looked at Zhao Lang with a tinge of regret.
Chapter 605, "The Plan to Surround and Annihilate Team Q Commences!", is the clearest early answer because it turns Su Yinwan's situation into a concrete plot event. The chapter gives readers a real answer by opening on The thirty-odd people lurking by the shore were just like today's...
Chapter 755, "You didn't fail to receive the invitation, did you?", is the clearest early answer because it turns Zhao Lang's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Shu Yan hadn't expected to earn so much even before she started her...
Chapter 838, "Just Call Me Grandpa", is the clearest early answer because it turns Yu Fei's situation into a concrete plot event. The setup is Gu Qiang's expression was subtle as well., but the pressure keeps building through By her reckoning, this was indeed her first encounter with the girl..
Chapter 2 is the strongest chapter-level answer because it starts from On the top floor of the Financial Building, a gathering of dark clouds... and follows through on Jiang, Lin Manru, turned pale and quickly explained, "It's not eloping, my....
Chapter 614, "Storm Crisis", is the clearest early answer because it turns Zhao Lang's situation into a concrete plot event. The chapter gives readers a real answer by opening on Today, the wind on the island was stronger, and for safety reasons,...
Chapter 672, "Wealth Brings Wealth, the Early Bird Catches the Worm!", is the clearest early answer because it turns Jiang Yan's situation into a concrete plot event. It opens with The president immediately stood upright, "We are all officially...
Chapter 776, "Sister Li Keeps a Toy Boy?", is the clearest early answer because it turns Jiang Shixu's situation into a concrete plot event. The chapter gives readers a real answer by opening on Apart from the two of them, some other users had started following...