mankai

In Yuuki Yuuna wa Yuusha de Aru, Mankai (Lit. Full Bloom) is a special power granted to Heroes who have expended a great deal of magic, granting its user incredible power unique to her for a limited time, at the cost of sacrificing one of her bodily functions to the Shinju called Sange.
Sange was soon removed from the system following the event where Tougou Mimori attempted to destroy the barrier.