In the mirror universe, the Capital Gain was a warship constructed by the Terran Rebellion, and was based on Defiant-class specifications stolen from Deep Space 9 in 2371. After the Terran Rebellion on Terok Nor in the mirror universe built their own Defiant, Zek and Bashir turned the abandoned Empok Nor station into a shipyard capable of producing up to twelve Defiant-class starships at one time. The Capital Gain was the first ship produced there, and was captained by Zek. (DS9 novel: Obsidian Alliances: "Saturn's Children")

Defiant-class destroyer/escort starships
Federation Starfleet	standard arrangement	Ajax • Alaska • Albatross • Aldebaran • Alexey Leonov • Armstrong • Ark Royal • Avenger • Baracus • Barracuda • Baton Rouge • Bennington • Boxer • Champion • Cheyenne • Cobra • Concord • Condor • Cormir • Corvus • Crockett • Dauntless • Defiant (I) • Defiant (II) • Eagle • Eclipse • Falkirk • Fargo • Formidable • Franklin • Gallant • Galahad • Gauntlet • Gawain • Grant • Halberd • Havoc • Helena • Horizon • Hornet • Hurricane • Illustrious • Incessant • Iwo Jima • Javelin • Kant • Kingfisher • Law • Lee • Leyte • Logan • Loki • Man-o-War • Matador • Maya • Medvedev • Merrimack • Michigan • Mongoose • Monitor (I) • Monitor (II) • Monsoon • Morgana • Moscow • Myrmidon • Narcissus • Neptune • Nomad • Pendragon • Pleiades • Potemkin • Python • Quillon • Ramses • Ranger • Raven • Redoubtable • Relentless • Renegade • Revere • Rockford • Rome • Saladin • Sao Paulo (I) • Sao Paulo (II) • Savannah • Scorpion • Sioux • Sirocco • Snake Eyes • Spitfire • Stalwart • Stromming • Tenacious • Thor • Ticonderoga • Titan • Treplev • Triumph • Triton • Tsunami • Turin • Valiant (I) • Valiant (II) • Valorous • Vanya • Victoria • Victorious • Vigilant • Voltaire • Warspite • Wasp • Wolverine • Zeppelin
	Incursion-subclass	Incursion
Terran Rebellion (mirror universe)		Capital Gain • Defiant • Jadzia • Terra Victor