The Nachthexen class was a 26th century Federation starship class, a battlecruiser and variant subclass of the 24th century Defiant-class escort, in Starfleet service during the in the 2550s decade. (STO - Agents of Yesterday short story: "No Profit But The Name")
Service history and specifications
The Nachthexen class was based on the Defiant-class escorts originally trialled in the in 2368 and launched in the year 2370. Among the tactical escorts of this class was the USS Defiant (NCC-75633-C), launched at some point before 2409. At the time, a cloaking device was standard equipment on tactical escorts. (STO - Klingon War mission: "Welcome to Earth Spacedock")
By the 26th century, the Nachthexen class operated as battlecruiser. This included the Defiant-C. By the 2550s, neither Benjamin Sisko nor Morrison had commanded the Nachthexen-class ship. Instead, the Defiant's commanding officer was Captain K'grel, daughter of Korol.
During the Temporal Cold War, the Defiant-C was assigned to the 5th Temporal Fleet. The Defiant destroyed the NV General Vosk, a Na'kuhl dreadnought and flagship of the 29th century battle group Virtuous Destiny. The conflict with the militant Na'kuhl faction left K'grel with scores to settle.
Ships of the class, including the Defiant-C, participated in the Battle of Procyon V alongside the USS Enterprise-J against the Temporal Liberation Front and their Sphere Builder allies in 2554. (STO - Agents of Yesterday short story: "No Profit But The Name", STO - Future Proof missions: "Ragnarok", "Battle of Procyon V")