The Destiny Ascension is an asari dreadnought from Mass Effect. It is the flagship of the Citadel Defense Fleet, and the most powerful dreadnought constructed by any of the Citadel Council races. Its main mass accelerator cannon is stated to be able to punch through the kinetic barriers of any ship in the Systems Alliance fleet. It has a crew of 10,000 and is commanded by Matriarch Lidanya.
The Destiny Ascension led the Citadel Defense Fleet in the Battle of the Citadel in 2183, where the Reaper Sovereign and a Heretic geth fleet attacked the Citadel. The Citadel Council was evacuated to the ship during the battle. Despite the Destiny Ascension's reputation, it was no match for Sovereign.
Depending on the choices of Commander Shepard, the dreadnought may be saved from destruction by the Systems Alliance Fifth Fleet clearing away geth ships or left to be destroyed by instructing the Fifth Fleet to ignore it in favor of attacking Sovereign.
If the Destiny Ascension survives the Battle of the Citadel, during the Reaper Invasion in 2186 it joins the multiracial task force called Sword Fleet. Sword Fleet made an attack on the Reaper occupied Earth in a last ditch effort to defeat the Reapers and end their invasion.