The TIE/D Defender, commonly known as the TIE Defender, is a starfighter available to the Imperial Remnant in Eras 1–5. It carries an armament of 4 Laser Cannons, 2 Medium Ion Cannons, and 2 Concussion Missiles.
The Empire's loss at the Battle of Yavin forced it to reconsider its tactics against the Rebellion. Several new weapons were initiated, such as the Lancer Frigate and TIE/in Interceptor. Also among these was the TIE Defender. Such was the importance of this project that it was kept secret from most of the Imperial Bureaucracy, conducted under the supervision of top naval commanders such as Grand Admiral Demetrius Zaarin. The original prototype was the TIE Advanced x7. Lacking the shields, hyperdrive, ion engines, and weaponry of the final model, it was intended merely as a test bed for new drive and targeting systems. By 3 ABY, the x7 had missile launchers added but lacked the ion cannons and speed of the final model; this led to several being destroyed during the Assault on Hoth.
Following the Battle of Hoth, Grand Admiral Zaarin was placed in direct control of all continued development of the TIE Series (the TIE Avenger and Defender). Upon acquiring a small yet easily mass produced hyperdrive from the Habeen, six models of the TIE Defender were transported to Coruscant for the Emperor's personal review. After the Emperor had given it his approval, the Defender was introduced to a few select squadrons for field testing. Although the design was brilliant and suffered few if any flaws, it received an icy reception from the Imperial Hierarchy, who resented not being informed of its production and felt it acknowledged an error in the Imperial Philosophy. In the end, field tests were not extensive, and the high cost of the fighter meant it would never be mass-produced as a frontline ship.
The most extensive use of the TIE Defender in the Galactic Civil war was during the attempted coup led by none other than Grand Admiral Zaarin himself. TIE Defenders were fielded on both sides in this conflict; in fact, they were considered so important to the war effort of both sides that construction facilities were destroyed and a ship specifically designed to combat it was designed. On several occasions, the Rebellion attempted to secure the technology for themselves. Seeing the danger this would pose (a three-sided war in which the balance of power depended on which side had the better starfighter pilots), once the Empire secured their own production of the TIE Defender they led a campaign to prevent the spread of said technology. Once Zaarin was finally brought to justice, it seemed that normalcy would return.
At least one squad of TIE Defenders (Onyx Squadron) fought during the Battle of Endor. However, because the Empire had lost so many during the hunt for Zaarin, only a small number were present during the battle. Their limited numbers could not secure a victory for the Empire. With the Emperor dead and his Empire crumbling, the cost of the TIE Defender became an even greater factor, and the model was practically discontinued. The ship would see only sporadic use until the return of Grand Admiral Thrawn; even then, their use was minimal, and their only real use was to patrol the borders of what would soon become the Imperial Remnant. They would remain in limited use throughout the Imperial Civil War, only given in small numbers to the best Imperial pilots (such as the 181st). Despite the long-standing hatred toward them, they would once again see active service in larger numbers during the Yuuzhan Vong War. Later, in 40 ABY, TIE Defenders were still part of the complement of Jag Fel's flagship the Gilad Pellaeon, as their speed, maneuverability, and firepower were still nearly unmatched.
The TIE Defender is the most advanced starfighter available in Thrawn's Revenge. In a faction that puts little or no emphasis on the quality of its starfighters, the TIE Defender is a drastic departure. While not quite the overpowered beast they were in Forces of Corruption, the Defender is still incredibly effective, even in later Eras. Combining the weaponry of a TIE Interceptor, the Ion Cannons of a Y-wing, and the concussion missiles and maneuverability of an A-wing resulted in a starfighter with no equal. Because of its Ion Cannons and Concussion Missiles, it also functions as a light bomber.
The TIE Defender has no weaknesses beyond what are common to all fighters. Keep it away from corvettes, other antifighter ships, and from being overwhelmed and it will be just fine. In short, the TIE Defender is the best dogfighter there is and should always be fielded if fighter superiority is in question.