Schirach

Schirach (シェラハ "Sherah"), also known as Schiele, is the second oldest of the three Gods of evil in Romancing SaGa. It is also hinted at that she may be the most powerful of the three.

Minstrel Song
After the battle of the Gods, Schirach and Elore met. Her powers were so great that if left unchecked, she would bring ruin to the world. It is said that her power of darkness rivaled Elore's power of light. Both the Red and Silver Moons were created to weaken her. It was afterwards that Elore and Schirach made a deal; she was given a Fatestone, the Diamond of Light. When her power of darkness met Elore's power of light, they cancelled each other out, thus rendering her harmless. It was then that she was turned into a mortal girl named Schiele. Thus, she traveled the world as Schiele under the watchful eye of Elore. Schiele has a tragic past, and everyone she meets has an unfortunate death and is tormented by countless accidents that takes the lives of the people closest to her. She is filled with despair and fear of her own power throughout her life. As Schiele, she has only known sadness. In the quest to gather the Fatestones, Scorn attacks Schiele while she shares a tale of the passing of someone she held dear with the Heroes. The lead will fight against Scorn to protect her. Win or lose, she will forcibly take the ring off in exchange for the safety of the lead character. This causes her to reawaken as Schirach. Now returned to her old self, fears the the world will be engulfed by her darkness. She asks the Heroes to defeat her and put her back to sleep. With her defeat, she returns to being a mortal and falls into a deep slumber.

Ultimate Boss
Schirach is one of the strongest opponents in the game. Both her CHA and INT stats are 99 and her techniques can inflict status ailments. Hymn of the Night Wind inflicts Phobia, Black Book inflicts Sleep, and Dark Temptation inflicts Charm and can take HP/LP from the Target. She can also inflict instant death with Abyss.

Video of the few cutscenes with Schiele and the battle with Schirach: Part 1, Part 2.

Trivia

 * Shirach never formally appears in the original SFC version of the game. Her portrait and backstory concerning the war with Elore is featured in the game intro, and sprite bearing her official artwork appears in Pub's, but she never says anything. It's believed there was suppose to a be a quest involving her. Hacking the game data shows that she was meant to be a recruitable character, and she does actually have a battle sprite with spell casting animations. Further evidence comes from a Japanese websites that discovered she had the Diamond Fatestone, though her identity as the human incarnation of Shirach was unknown.