Genkai

From Yoshihiro Togashi's manga and anime Yu Yu Hakusho, there is a character named Genkai. Yusuke Urameshi, the main character, is sent to train under Genkai, an elderly chi-master, in order to learn the fabled "Spirit Wave" method. As the series' strongest full-blooded human, Genkai is revered as the scourge of the demon race despite her diminutive stature and fragile appearance. Not only is Genkai significantly more skilled with spirit energy than Yusuke, but he is also even more aggressive, caustic, and pugilistic than Yusuke.

Although Genkai frequently gave the impression that she was heartless and that sometimes, the means justify the ends, she finally started to treat Yusuke like her grandson. Similar to Yusuke and Hiei, Genkai is typically irritable and highly grounded. In contrast to Hiei and Yusuke, Genkai also has a dark sense of humor. If for no other reason than to play with her apprentice, she will go to great lengths to intimidate Yusuke, even at the risk of her own life.

The main reason Genkai keeps her identity a secret or withdraws into herself as a recluse is to avoid dealing with the legions of demons that would flock to her in an attempt to gain notoriety. Genkai is almost never taken off guard and comes across as completely jaded to any and all situations because she always plans for the worst case scenario before engaging in any kind of conflict or other type of issue.

Anime: Yu Yu Hakusho