As Arlan displayed on his flawed, but first board, Proteus, There were times a character may gain or lose a trait. The same is here. You may gain and lose traits as you progress, and descriptions for gained traits will appear here...
Duplication - After her experience in the strange Graveyard, Yuki has gained a newfound 'power' it seems. By concentrating, Yuki can make duplicates of herself up to her current level power level. If she has items that increase her own power level, they also add onto the clone amount.