Echidna

Echidna is the demon lord who said to be anniliate the mankind. After being defeated by Leo Demonheart, she had to back off with her army. She is the titular female protagonist of the Yuusha, Yamemasu series.

Appearance
Echidna is a woman of average height. She has horns and long, flowing pink hair reaching some way down past her shoulders. She has deep, golden-colored eyes. She wears one paired of red earrings, thigh-high boots, a red dress along with a black belt having a golden suspender.

Even though she has a young and beautiful woman's appearance, she is over a hundred years old.

Personality
It is said that she is unruly and cruel person. Despite of these rumors, Echidna is generally easy-going, cheerful, and relaxed. As long as she isn't directly provoked, she's perfectly fine with "live and let live," although she occasionally voices the desire to burn up people en masse when she gets impatient. Echidna is really different from her ancestors which shown when she gave the order to avoid any unnecessary bloodshed and  told her subordinates to rule the occupied territories in peace.

Though an imposing and intelligent woman, she has shown a bit of a childish and comedic side.

Background
The so-known "Demon Lord" who tries to invade human world in order to retrieve the Philosopher's Stone.