Lady Sirella is the head of the Klingon Great House of Martok since the apparent death of her husband, Chancellor Martok, in 2393. In 2410, Martok returned and led his house once again after his liberation from the Son'a Facility 617 prison.
- “Bringing Down the House”: Sirella suspects an assassin is about to strike against her house. Actually the Romulan Tarsen is discovered, who eventually manages to kill M'ven, Sirella's grandson, on Forcas III.
- “Brushfire”: Sirella and Worf arrive at the Briar Patch with a fleet of Klingon ships to assist the player and General Rodek's rescue of General Martok from Torg, the Son'a, and the Tzenkethi.
- “Storm Clouds Gather”: Sirella and her husband Martok accompany Chancellor J'mpok to Deep Space 9 for an Alliance summit on the Hur'q threat.
- “The House Always Wins”: Sirella calls the player to the Martok estates to participate in the Ak'voh for M'ven. When forces loyal to the House of Torg attack during the ceremony, Sirella swears she will have revenge.
- "New Featured Episode: Brushfire": Sirella visits General Rodek, who is preparing the I.K.S. Kor to depart on a mission to rescue Martok from the Son'a, having helped him plan the operation before it was presented to J'mpok and the High Council. She urges Rodek to, if it comes to it, send his ship to the edge of the Briar Patch to make Torg pay for the death of M'ven.
- Prior to the Year of Klingon, Sirella's cranial ridge pattern and skin complexion were substantially different from how they are depicted on Star Trek: Deep Space Nine. She was also voiced by Lani Minella. In Fall 2020 her appearance was updated to match her look on the show, and Shannon Cochran joined as a voice actor to reprise her role.
Klingon Defense Force
|Details||Klingon Defense Force • Klingon Empire • Klingon • Gorn • Orion • Nausicaan • Lethean • Ferasan • Great House • Qo'noS • Klingon Academy • Rura Penthe • Boreth • Ganalda Station|
|Ground Forces||War Targ • Bekk • Warrior • Officer • Munitions Officer • Targ Handler • Swordmaster • Dahar Master|
|Starships||To'Duj Fighter • Bird-of-Prey (Prime Timeline) • Bird-of-Prey (Kelvin Timeline) • Raptor Escort • Klingon Battle Cruiser • Negh'Var Warship • Vo'Quv Dreadnought • Bortasqu' Dreadnought Battlecruiser|
|NPCs||B'vat • Galera • J'mpok • Ja'rod • Jurlek • K'Gan • K'men • K'Valk • Kagran • Kahless • Koren • Martok • Nin'Yan • Rodek • Alexander Rozhenko • Sirella • Temek • Torg • Worf|
|NPC starships||I.K.S. Batlh • I.K.S. Bortasqu' • I.K.S. Chot • I.K.S. Kal'Ruq • I.K.S. Kang • I.K.S. Kor • I.K.S. Kri’stak • I.K.S. Lukara • I.K.V. Quv • I.K.S. Seg'pa • I.K.S. Rotarran • I.K.S. Targ (B'rel class) • I.K.S. Targ (Klothos class) • I.K.S. Worvig|