It might make some characters jealous. For instance, if the Sacred Gear gives Percy an edge in combat, some of his fellow demigods who are used to being on equal footing with him could start to feel envious.
Perhaps the Sacred Gear has a mind of its own. It could communicate with Percy in his dreams or during times of great stress. The Sacred Gear might have its own goals and motives that don't always align with Percy's. This internal conflict, along with external threats, would make for a very interesting and complex fanfiction.
One idea could be that Percy discovers a new kind of Sacred Gear during one of his quests. Maybe it has the power to control water in a completely different way than his normal abilities. Another could be a crossover where Percy and a character with a Sacred Gear team up to defeat a common enemy that neither could face alone.
Issei Hyoudou would be an obvious choice. Since he's a well - known character associated with Sacred Gears. His interactions with Percy could be really interesting as they come from different power systems. Another could be Kiba Yuuto, also from the Sacred Gear universe, his sword - based abilities could contrast well with Percy's water powers.
Naruto's confidence would likely skyrocket. Having a Sacred Gear would be like having an extra ace up his sleeve. He'd become more fearless in battles, knowing he has this new power. His relationships might also change. His friends would be both in awe and a bit worried about this new development. He'd have to learn to control the Sacred Gear, which would be a new kind of training for him, making him more disciplined.
One possible power of Naruto's Sacred Gear could be the ability to phase through objects. This would give him an edge in combat as he could dodge attacks easily. It might also have a power related to healing. Since Naruto is often in the thick of battle and gets injured, a self - healing Sacred Gear would be very useful. Additionally, it could have a power that allows Naruto to communicate with animals on a deeper level, like understanding their thoughts and using them to his advantage in battles or for gathering information.
Well, it would completely change the power dynamics in the Harry Potter universe. A Sacred Gear is a powerful object from another fictional context, and if Harry had one, he might become even more of a force to be reckoned with against Voldemort. It could also lead to new and interesting magical abilities that we haven't seen in the original series.
Voldemort could still be a main antagonist. He might be especially interested in Harry's Sacred Gear because it could potentially give Harry an edge over him in their battles.
One possible plotline could be Harry using his Sacred Gear to fight against powerful dark wizards in the Harry Potter universe. It might give him unique powers that he has to learn to control.
The most interesting part is the combination of two different and exciting concepts. Percy Jackson's world is full of Greek mythology and adventure, while Boosted Gear brings in a unique power - up system. When combined, it creates a whole new set of possibilities for the story.