BackgroundEditAfter F.L.E.I.J.A. was developed by Nina and was used by Suzaku Kururugi during the Second Assault on Tokyo Settlement, it was deemed a major success as a weapon. A month afterward, the Toromo Agency managed to mass produce them and mounted several of them on Schneizel's sky fortress, the Damocles. Lelouch, knowing that the F.L.E.I.J.A. would be a major obstacle in the final battle, has Lloyd retrieve Nina from Ashford Academy in order to develop a countermeasure for it. Along with Lloyd and Cecile, Nina was able to develop the F.L.E.I.J.A. Eliminator.
After it was finished developed, it was attached to Lelouch's Shinkirō, who was the one who inputted the data and then was executed by Suzaku and his Lancelot Albion thus was able to stop the F.L.E.I.J.A. meant for them. Schneizel, Kanon and Diethard were shocked that Lelouch had this, allowing enough time for them to breach through the Damocles' Blaze Luminous.
Being a countermeasure for F.L.E.I.J.A., it takes advantage of F.L.E.I.J.A.'s ever-changing composition and bombards it with a reaction that counters its composition thus preventing it from reaching its criticality. It takes a form of a staff with one end that has three green protruding rods and a pink crystal in the middle which is presumably the reaction that will bombard the F.L.E.I.J.A.'s composition. It also has many layers that will be disintegrated in the process of countering its composition.
- Enter the local environment data into the system in 19 seconds before detonation. The environment data is based on temperature and distance along with the timing of when the F.L.E.I.J.A. launched requiring great skill, coordination, and perceptive and analysis abilities.
- After the data has loaded in less than 19 seconds or earlier, the eliminator must be launched and impacted with the solid hull of the enemy warhead between the time the warhead starts to detonate and before it unleashes it diffusing energy, a time period of 0.04 seconds. If detonated earlier, the canceller will trigger the F.L.E.I.J.A. to detonate and destroy the canceller. If detonated later, the F.L.E.I.J.A. will detonate and destroy the canceller by itself.