One possible new power could be the power to absorb and use any chakra, regardless of its origin. This would make him extremely powerful as he could draw from the chakra of his enemies or even from natural sources like the sun or the earth. He could also gain the power of telepathy on a large scale, being able to communicate with anyone in the world or even across different dimensions. Additionally, he might obtain the power of instant teleportation to any place he desires, which would give him a huge advantage in battles and travels.
Well, Yukio acquires powers in the manga. These powers play a crucial role in shaping the plot and his character arc. They give him new abilities and challenges to face.
In the manga, Reigen doesn't have powers. His charm and appeal come from his down-to-earth nature and the way he navigates the supernatural world without relying on extraordinary abilities.
In the comics, Darcy remains without powers. The story focuses more on her character development and involvement in other aspects rather than giving her any special abilities.