Castle Full of Blackbirds

On the night of winter solstice in 2020, the world was caught by surprise as every black person suddenly gained a set of superpowers they did not have the day before. As the next winter solstice approaches everyone anxiously awaits whether their superpowers will come back. Meanwhile, a group of siblings have conceived the ultimate plan to use their powers - which they're sure will come back - for the greater good even as everyone else tries to stop them.