Isha is one of the two alters that Futari has, she's the more sadistic and dangerous of the three. She's not afraid to move into something new head on, especially if there's a risk vs reward element to it.

She started appearing once Futari had to perform surgery in a hospital setting, she immediately took the reigns of Futari and completed the surgery with a success. Once Nephthys was able to give her full control of Futari's body, she almost didn't want to let it go, but Nephthys convinced her to share through threatening that she erase her from the girl's mind, to which she followed her orders immediately.

Backstory

While she doesn't have memories or the sort, she would often only appear if Futari had completely tired herself out. Sometimes she could control a limb, sometimes an eye, other times, she would linger in Futari's thoughts. It was nothing dangerous at first, but as the years went on and Futari was nearing the end of college, Isha became a prominent figure that encouraged Futari to abandon her friends and focus on her studies. This is where Futari noticed that this voice wasn't her own, and thus, shut herself in her dorm.

It didn't take long before rumor started to spread around of the capability doctor, and Isha, being oh so curious, convinced Futari to head over. Once she went under anesthesia, Nephthys brought out Isha first, as she's the one who's been controlling Futari, but Nephthys threw her into a "blank room", one that allowed her to talk with her alters.

Present

Sharing wasn't her best form of expression, but she was willing to do it if it was to perform surgery or to talk to Nephthys. She also spends most of her time dormant in Futari's brain. Isha grew especially close with Dokuta, her other alter, since they had assumed they were married from the start. The brunette also researched more on surgery, to the point where she's trusted to perform brain and open heart surgery. She hates being taken away from her work in the middle of it, but only will if it's one of her alters or Nephthys herself.

If Nephthys wants a target eliminated and Nikushimi isn't there, Isha takes it upon herself to purge them from the world. She loves wielding a chainsaw, but is willing to admit there is something funny about the scalpel as a weapon choice. She owes her very life to Nephthys and will treat it as the last day she has as an alter.