The Schwarzkreuz (lit. Black Cross) is a magic-user organization debuting in Rosenkreuzstilette Freudenstachel as rivals of fellow magic-user organization RKS. Its creation was overseen by Holy Empire and Orthodox Church in response to RKS's rebellion.
The organization is made up of a type of Magus called Dark Magi, and they make up their home base in a church controlled by the Holy Empire. They are led and captained by one such Magus named Pamela Arwig.
In their debut in Rosenkreuzstilette Freudenstachel, the Schwarzkreuz launched its own witch-hunting coup against RKS in terms of putting down the Walpurgisnacht, that while having Spiritia Rosenberg kidnapped. They are fought right after Freudia Neuwahl defeats her friends and colleagues at RKS in order to convince them that she's not a homunculus and informs them of Tia's disappearance and the threat of the Schwarzkreuz itself. The Schwarzkreuz later resigns after Freu learns that Iris and Eifer had disposed of their pope and been manipulating them all along.
- SK001 Eins: Pamela Arwig (leader, captain)
- SK002 Zwei: Eifer Skute (turned traitor later)
- SK003 Drei: Schirach Fühler (former RKS member)
- SK004 Vier: Lecht Refraktia
- SK005 Fünf: Rink Refraktia (mirror image created by Lecht)
- The designs of the members of the Schwarzkreuz resemble characters from various Eroge computer and video games.
- The english translation for the name of the Schwarzkreuz is similar to that of the Black Cross Army, the first villains to appear in the Super Sentai franchise and the main villains of Himitsu Sentai Goranger.
- The Schwarzkreuz is similar to the X-Hunters from Mega Man X2. They both spied on their respective hero through a viewing globe within their headquarters, and they were both thought to be the primary antagonists until an unexpected villain was revealed to be the true antagonist (Iris Sepperin and Eifer for the Schwarzkreuz and Sigma for the X-Hunters).
- Like RKS, the Schwarzkreuz also have their own ID numbers. Of course, their ID numbers only contain two letters as opposed to RKS's three.