Misaka Seigen

Misaka Seigen, is an Amatsuotome who currently resides in the spiritual realm Paradiso. Brought up there after her death, Misaka is quite experienced and rather old, despite her appearance and personality and ages well over 1000 years of age. Misaka was taught how to defend herself and others from an ancient Amatsuotome who was born only a few decades after Minako Kichida and died after defending Misaka from an unnamed attacker in Paradiso many years ago. Since then, she has become friends with Kaede Nobuko, and is known to be extremely accepting and trusting, as well as Kaede being her "guardian" in a sense, protecting her from those with malicious intentions.

Behind the Scenes
Her appearance is based off Tendo Rushuna from Grenadier

Some of her personality and some parts of her fighting style are influenced by Tendo Rushuna from the anime series Grenadier, although not completely.