
Egil is an antagonist of Xenoblade Chronicles. He is a member of a race of mechanical lifeforms known as Machina.
He doesn't show up until Shulk and his group reincountered Fiora and Mumkhar just before reaching Sword Valley. Revealing himself to be responsible for the Mechon attacks on the Bionis, the group intends on stopping him. His reasons for attacking Bionis and its inhabitants stems on what occurred a few thousand years ago.
Prior to that, the Bionis and Mechonis lived together in harmony as did the inhabitants of both titans. Egil befriended a friendly giant named Arglas. At one point, they discussed the future that their descendants would like to live. However, the Bionis sent Telethia to attack the Machina within their city of Agniratha, wiping out almost all of the Machina population. From this, Egil, enraged by the near genocide of his people, swore vengence against the Bionis. He constructed the Mechon to attack the inhabitants of Bionis as a means of cutting off the Bionis' food supplies. That battle had continue for a few thousand years.
However, his Mechon were being outmatched by the Monado, used by Dunban during the Battle at Sword Valley, prompting Egil to abduct Homs and use them as pilots for his newly constructed Mechon that consist of metal faces. These Mechon became resistant to the Monado as the Monado, at the time, couldn't harm people. However, that weakness became null void from the group's visit at Prison Island.
Later on, Egil gained full control of the Mechonis, becoming it's pilot. Shulk and his friends fought against Egil and won but Shulk refused to deliver the finishing blow, stating that he intends to continue fighting Egil until he finally gets him to stop fighting. Egil was impressed by Shulk's courage and determination to end the ongoing battles and the two at the time agreed to a truce, with Egil having remembered when the Bionis and the Mechonis lived in peace.
The two were about to come to a truce until Dickson shot Shulk in the back and revealed why the Bionis attacked the Mechonis. From there, Zanza, the embodiment of the Bionis, emerged from Shulk's body, taking the Monado. Zanza returned to the Bionis and took back control of his body. Egil decided to stay behind within the Mechonis to try and stop the Bionis while the group escaped. Egil died within the Mechonis, glad to have given his life to play his part.