The elder of the two Xi twins was destined for a life of glory from the very beginning. Where her sister failed in developing the Xi bloodline, she did not. She quickly excelled in the Xi’s unique doujutsu and shockwave techniques and was rewarded for her success with a life of luxury as one of the Xi’s glorified ancient protectors, those who would be charged with protecting all of the secrets of the Xi clan.
Despite resistance on her part, true Ukime would steal those secrets easily upon claiming her body and mind which would eventually lead to the slow decline of the Xi clan as one of their own violently turned against them and slaughtered every other protector without remorse.
As the younger sister, too, became a victim of Ukime’s domination the two sisters shifted allegiance from Iwagakure to Kumogakure and formed a premier bounty hunting duo, dubbing themselves ‘The Hardcore Twins’. Together and with Ukime’s power backing them the two have shown incredible ability, raking in piles of cash like no tomorrow as they’ve become the number one bounty hunters in the world. In some cases villages come to them over even their own hunter-nin.
Xi Mari was given a moderate amount of Ukime’s powers. Standard weapons and attacks can wound or harm her, but she possesses an incredible ability to repair any part of her body. Every cell of her body possesses its own mind and memory and so long as a single cell remains she can rebuild herself back to perfect health. How long a repair may take depends largely on the severity of her injury.
It has been shown that when she and her sister cross blood they each gain a portion of the other’s ability. Whether this is unique or possible with any Ukime is currently unknown.