SUMMARY
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The Sternritter was created by Yhwach to attack Soul Society.
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Each member is given a Schrift, a unique power from Yhwach.
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When they are gone, their strength returns to Jehovah, making Him stronger.
Among the ranks of the Wandenreich, the Sternritter are twenty-six Quincy who were given Schrift by their king, Yhwach. Each of them possessing unique spiritual weapons and powers, the Sternritter has proven to be the deadliest enemy the Gotei 13 have faced. Although they are not all created equal, each member of the the corps can stand up to strong Shinigami captains and lieutenants.
Bleach Millennium War revealed how Yhwach created the powerful Quincy team. Here's everything you need to know about the creation of the Sternritter, the Holy Knights of the Wandenreich.

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The creation of the Sternritter
The Star-Cross Knights
A thousand years before the beginning of the bleach series, Yhwach is the king of the Licht Reich, the Empire of Light. He conquered and dominated part of the Middle Ages of the Living. Scattered and disorganized, the Quincy spread throughout the human world. The most powerful Quincy worked under Yhwach, who exterminated and banished his fellow Quincy who disobeyed him. He is assisted by his King's Guard, the first iteration of which includes Argola Lallau, Hubert Alexander Kleich, Johann Seydlitz, and Nikita Deathlok.
“Within the Seireitei they created a secret place of Reishi for themselves in the shadow of every city… And this kingdom was named our “secret kingdom”: the Wandenreich.
During a meeting with Johann Seydlitz, Yhwach decided to form his own army. A group of powerful Quincy people he will call The Sternritter (Star-Cross Knights). He will use this military power to invade and attack the Soul Society to destroy the Soul Reapers and kill the Soul King Adnyeus. Yhwach will give each member of the Sternritter authority a Schrift.

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How is Sternritter empowered?
The Father gives, the Father takes
Yhwach is the father of all Quincy. He is gifted with unique powers that allow him to share his power with others. Most Quincy can gather spiritual elements from their environment to empower themselves and create spiritual weapons. However, Yhwach does not have this ability. Instead, he shares his soul with his children. By sharing his spiritual pressure with other Quincy, he can bring out the true power of their souls and give them Schrift. Through carving rituals, the Sternritter gained power over the king and his father. In the ritual, the Quincy must drink Yhwach's blood. In doing so, Yhwach carved into their souls. According to their spirit and personality, the letter assigned to them gives them a special power that they use in battle, Schrift. Each Schrift is assigned to each Sternritter on its own merits.
Sternritter F – Äs Nodt is gifted with the power of The Fear, the ability to instill extreme and irrational fear in his enemies. This ability was awakened in him by his fear of pain and death. He was terminally ill, and he was afraid of dying. He was afraid of going to hell. In his agony, Yhwach appeared before him and saved him, transforming him into a Mover. It is believed that the Aüswahlen caused Äs Nodt's suffering.
“I must thank the souls of the dead. Another day when I can see the world clearly.”
Because each Sternritter has a part of Yhwach's soul within them, when they die, this power returns to Yhwach, gradually increasing his power. Jehovah gives power to his children, and when they die, that power will return to them. Quincy's father is a giver, and his father is a taker.

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Sternritter Subgroups
Designated team
Although the Sternritter are a large military force, they have two groups that show a distinct division in their ranks. One of them is designated by his gender, while the other is by a greater power and closer to his king. Additionally, the Sternritter is not only Yhwach's subordinate, but also his right-hand man. Sternritter B – Jugram Haschwalth is the head of the Sternritter, the leader of the corps. This is due to his bond with Yhwach and his undying loyalty.
The Bambies are the all female group within Sternritter. They are the only female members of the corps, and so they come together as a group. They are named after the unofficial leader of the Sternritter E group – Bambietta Basterbine. The other four members are Sternritter G – Liltotto Lamperd, Sternritter T – Candice Catnipp, Sternritter P – Meninas McAllon, and Sternritter Z – Giselle Gewelle. Liltotto and Giselle are the only ones left in the group, because the other three were killed during the second attack and the Aüswahlen and then led by Giselle.
The Royal Guards or Schutztaffel are the senior members of the Sternritter. Yhwach's closest and strongest Quincy in the Wandenreich. Their leader is Sternritter X – Lille Barro, who is also the first Quincy to be given a Schrift. The other members are Sternritter M – Gerard Valkyrie, Sternritter C – Pernida Parnkgjas, Sternritter D – Askin Nakk le Vaar and Sternritter A – Uryuu Ishida.
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The Sternritter was created by Yhwach to attack Soul Society.
-
Each member is given a Schrift, a unique power from Yhwach.
-
When they are gone, their strength returns to Jehovah, making Him stronger.
The Sternritter was Yhwach's elite soldier during his holy war against Soul Society. Currently, most of them have fallen in battle with the Gotei 13 or other members of the Corps.

Bleach: A Thousand Years of Blood War