Riesbyfe

Another name for the female knight who is a Shield Knight. It's said that in order to save Sion, she was supposedly killed by TATARI 3 years prior to the events of Melty Blood. In the Tsuki-Bako PLUS+DISC “Getcha2” corner, we learned that originally she was going to be the main heroine in Melty Blood, and Ciel's rival. It seems that her weapon is a pile bunker1. It would be nice to see a showdown between Riesbyfe's pile bunker, and Ciel's Seventh Holy Scripture.

MB Official Strategy Guide: Melty Blood Glossary
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Principal of Reien Girls Academy. Age unknown.
A pious Christian. When energized, she would engage in overzealous philanthropic activities due to her excessive faith.
The principal's office was decorated with a shield that would invoke the image of a violin.
Originally she was not an important character that would warrant an entry in this glossary, but since she showed up in other works, I had to pick her up.

Garden of sinners Pamphlet: Kara no Kyoukai Settings Glossary
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Knight of the Shield. Captain of the Knights of the Inquisition led by the Holy Church. Female.
She participated in the failed subjugation of Wallachia alongside Sion, and faced Wallachia alone so that Sion could escape. Her fate afterward is unknown. She possesses the conceptual weapon “True Apocrypha Gamaliel,” a gun-shield that superficially resembles a large stringed instrument.
Though it seems Sion thought of her as reliable, they were torn apart before either of them realized they had become friends.
During Vampire Sion's Last Arc, she attacks the enemy by recreating Riesbyfe's information. Apparently, since Riesbyfe was swallowed up by the Tatari, she was transferred into Vampire Sion when she inherited its power.
Also, though there is apparently a nun with the same name working at a certain academy for girls, it is unknown if they are actually the same person or not.

Tsukihime Dokuhon Plus Period: Tsukihime Dictionary Revised
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Knight of the Shield. Captain of the Knights of the Inquisition led by the Holy Church.
She participated in the subjugation of the Tatari three years ago, and faced Wallachia alone so that Sion could escape. Her fate afterward is unknown. She possesses the conceptual weapon “True Apocrypha Gamaliel,” a gun-shield that superficially resembles a large stringed instrument.
Though it seems Sion thought of her as reliable, they were torn apart before either of them realized they had become friends.
During Vampire Sion's Last Arc, she attacks the enemy by recreating Riesbyfe's information. Apparently, since Riesbyfe was swallowed up by the Tatari, she was transferred into Vampire Sion when she inherited its power.
Properly speaking, because everything swallowed by the Tatari is reconfigured as equivalent data, things that can be recreated separately from the Tatari like Riesbyfe are rare. Presumably, it's due to the presence of the True Apocrypha, acting as a shield and slowing her absorption.

MB Act Cadenza PS2 Manual: Tsukihime Dictionary
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riesbyfe
Translator's Notes
  1. ^ From Armored Trooper VOTOMS.