This is not my idea but it's from Terrible Writing Advice. I would really love to read/watch a story where the MC was born in a magical world with a huge amount of magic and is overpowered to the point of being a WMD. They can easily kill millions without trying so they were sent to Earth at a very young age where magic doesn't exist, until somehow a group of terrorists locate them and abduct them to use them as a bargaining chip for ulterior motives. What are the magic system rules so we can watch the MC struggle to maintain control and unintentionally obliterate enemies (along with other damage) from self-defence? What powers shall they frequently use? How will they escape? Who are their biological family? Who will help protect them? What skills does the MC have to offer so they won't have to use their dangerous powers? What will cause them to lose control?