Jao Shingan (じゃおうしんがん), is from the Japanese anime and light novel series "Love, Chunibyo & Other Delusions." The female protagonist, Takanashi Rikka, covers her right eye, which has a golden iris colored contact lens, with an eyepatch. This is the signature mark of her "chunibyo" and "evil eye" persona. Thus, Rikka's self-proclaimed identity is the "Wielder of the Jao Shingan (Japanese original: 邪王真眼の使い手)."
Rikka believes her father is in a parallel world beyond the "Unseen Boundary." Under the "guidance" of the middle-school-era Yuta, she obtained the power of the Jao Shingan in her quest to find this "Unseen Boundary." (This also embodies Rikka's hopes for her father.)
Because she believes in things that ordinary people deem impossible, because she holds faith in things ordinary people deem impossible, she has obtained power that surpasses the ordinary. —This is the so-called 'Jao Shingan'.
Jao Shingan:
Five-star, max level:
Skill One - Jao Shingan: Every 5 seconds, randomly applies a Death Mark to a normal enemy. Attacking a marked enemy will kill it instantly.
Skill Two - Dark Bible: Increases weapon critical hit chance by 33.53%.
Six-star, max level:
Skill One - Jao Shingan: Every 4.25 seconds, randomly applies a Death Mark to a normal enemy. Attacking a marked enemy will kill it instantly.
Skill Two - Dark Bible: Increases weapon critical hit chance by 43.61%.
Looking at the skills, the five and six-star 'Jao Shingan' is quite strong for its crit rate boost, but its other ability is a bit lackluster, only useful for killing mobs. A shame to discard, but tasteless to keep.
But everything changes when the Jao Shingan is upgraded to seven stars.
Seven-star Supreme Divine Weapon, 'Jao Shingan: Yami':
Skill One - Evil Eye of Direct Death: Every 5 seconds, mark an enemy. Attacks will instantly kill normal enemies or deal 80% additional damage to stronger enemies.
Skill Two - Dark Bible: Increases weapon critical hit chance by 50%.
Upgraded to seven stars, the 'Jao Shingan' is like a phoenix reborn. With its massive boost to weapon criticals and super-strong buff for single-target boss fights, it is truly worthy of the seven-star name!