Kakashi could also be included. He has a history with Obito, and his relationship with Itachi was also complex. His skills and his role as a mentor - like figure can bring a different dynamic to the story. For example, he could be the one who suspects something strange is going on between Itachi and Obito and tries to figure out their motives.
One idea could be a story where Itachi and Obito are forced to team up against a new, powerful enemy that threatens the ninja world. They start off distrusting each other due to their past actions, but as they face challenges together, they gradually come to understand and respect one another.
He expressed his love in many ways. For example, he was very concerned about Rin's well - being. Whenever she was in trouble, he would rush to her side without hesitation. He also blushed around her sometimes, which was a sign of his shyness and love for her.
In some fanfictions, Konan might use her origami techniques in a highly lethal way. Maybe she creates a large number of explosive paper bombs and traps Obito in a confined space, detonating them all at once to overpower his defenses and kill him.
In this fanfiction, Itachi might help Sakura become stronger by training her in various ninja skills. He could teach her advanced genjutsu techniques. For example, he might start with the basics of detecting and breaking genjutsu, and then gradually move on to creating complex illusions herself. This would enhance Sakura's ability to defend against and use genjutsu in battles.
Naruto could be one of his allies. Naruto has this knack for seeing the good in people and would probably be willing to give Obito a chance to redeem himself. Also, Sakura, with her skills as a medic - ninja, could be an ally. She might help heal Obito if he was injured during the war and see the potential in him to be a force for good.
There could also be interactions with the new generation of ninjas. They might view Obito as a sort of legend or a cautionary tale. Their fresh perspectives could either inspire Obito to change further or make him feel even more out of place in this new post - war ninja world.