[@Noxx]

I feel enough time has passed where I can give my thoughts to you now.

Her Devil Arm is fine. Her Magic however needs to be fine-tuned. For her Sunken World ability, I have the same questions and concerns as [@KoL], including limiting range of scope in area. Alternatively, I’m fine with her blood ability so long as you keep it to only buffing her with no extra abilities.

Her water magic as a whole, however, needs to be limited. I’ll accept direct water manipulation as well inorganic compounds; but no solid matter such as ice. We already have an ice-using Magical Girl and I don’t want the abilities being inter-mixed because by this logic, your character and [@Lonewolf685]’s Kanbaru can do the exact same thing. Limit her magic to direct water manipulation and inorganic compounds only.

Finally, her "Test of soul / Undertoe" ability. I would suggest either getting rid of it entirely or rewriting it to better fit her water theme. At the moment, this magic is too jarring in contrast to her other abilities nor is the aspect of curses expanded upon to what that actually means. It doesn’t seem to fit her overall.

As for her backstory, it looks fine to me. I’ll accept eldritch cults roaming about in Miso City; but I won’t accept that as her reason for becoming a Dark Magical Girl as that infringes too much on the established lore. 

Address these points and we’ll go from there.