In the first episode, Setsuna crashes the AEU's demonstration of their latest mobile suit model. Using Exia's superior power, Setsuna is able to easily destroy an Enact piloted by Patrick Colasour. The AEU then sends out more troops to try and stop Setsuna and Exia by overwhelming him with their numbers, however, Setsuna is not alone. Lockon shows his presence to the troops by sniping them from the ground. By showing off two of their mobile suits, Celestial Being was able to show the world the power they possess. The battle may be one-sided but the opening scene from the series does its job, getting you excited for what is to come.

While the other members of Celestial Being are battling against the UN Army, Lockon sets out to attack the base ships leading the UN's forces. Lockon is stopped by Ali al-Saachez and his newly acquired Gundam the Throne Zwei and the two engage in one of the best fights in the series. The battle starts with the duo exchanging gunfire before they eventually move over to close quarter combat. Lockon is blindsided by a former member of the Overflags, exposing Lockon's eye injury he suffered in a previous battle and allowing Ali al-Saachez to cause significant damage to Dynames. With Lockon determined to take out the man who killed his parents, he exits Dynames and takes Ali al-Saachez and the head on, sacrificing himself to take one final shot at stopping him. This fight has everything you could want out of a Gundam fight and more. Happening at the end of the first season the battle is just one of many going on during Celestial Beings battle with the UN Army, but it takes center stage thanks to its great action and the effect it has on the second season.

After a full season of episodes of build up, the battle between Setsuna and Graham finally took place in the final moments of episode 25. Graham arrives to battle Setsuna right after Setsuna finished his fight with the mastermind behind the attack on Celestial Being, Alejandro. With Graham and his Flag equipped with the GN Drive, he was able to go toe to toe with Setsuna and Exia. The battle continues with Setsuna and Graham and exchanging blows, as they manage to cut off parts of each other's mobile suits while they discuss their ideals and why they fight. The battle reaches a climax with both pilots stabbing each other resulting in significant damage to the Flag and Exia. Graham ends up receiving more damage and is spared by Setsuna, who leaves him stranded in space.