The Battle of Azura was the final battle between the remnants of the COG and Gorasni against the Locust in Azura and the Lambent where the Locust Queen made her last stand against Delta in an attempt to solve the Lambent threat.
During the Attack on the Sovereign, Chairman Richard Prescott returned and gave Marcus Fenix a message from his father Adam Fenix revealing he was still alive on the island of Azura and had a weapon that could destroy the Lambent and the Locust. The Locust were aware of this as well and during the First Battle of Azura captured the island and Adam and slaughtered everyone else to force Adam to refine his weapon so it wouldn't effect them. Learning of Azura from the message, Prescott and A2897, Marcus led a mission to Azura to save Adam and use the weapon, getting fuel from Char while sending Damon Baird, Clayton Carmine and Augustus Cole to gather reinforcements for the battle.
Order of Battle
Passage to Azura
After getting a submarine, Delta Squad and Dizzy Wallin traveled underwater to Azura, the only way to reach the island due to its Maelstrom barrier. On the way, they came under attack by Manglers and a Leviathan as well as passing through mines. After losing the Manglers in the current caused by the Maelstrom, and the Leviathan getting crushed by falling debris, they took out automated turrets and the torpedoes they fired, allowing the sub to arrive at the island safely and dock in an underground cave. Upon arrival, Delta had Dizzy take the sub to a safe distance as they knew it might be their only way off the island.
Attack on the Maelstrom Facility
After fighting their way out of the caves, Delta headed for the Maelstrom Facility to shut down the Maelstrom and allow Cole and Baird's reinforcements to come to the island. With the help of Adam Fenix guiding them from where he was locked in his lab, the group reached the facility fighting off a determined Locust attack all the way. Traveling to the basement, Delta shut down three generators powering the Maelstrom, but discovered that the Locust had apparently set up another power source they didn't have time to find. Following Adam's advice, they shut off five coolant valves to the device, which were protected by Armored Kantus and caused the facility to explode. Delta gets out in time and the Maelstrom is shut down, allowing Cole and Baird to arrive with Gorasni reinforcements led by Commander Miran Trescu.
Battle of Azura
With the reinforcements having arrived, Marcus, Cole, Baird and Anya Stroud headed off to rescue Adam Fenix as Samantha Byrne and Jace Stratton went off to help the Gorasni. As they fought through the increasingly desperate Locust forces on the way to Azura's Pinnacle Tower, the Locust shot a Gorasni King Raven down so Delta took several Siegebeasts and Gas Barges out to protect their reinforcements. Eventually, the group reached the Pinnacle Tower where the Lambent joined the fight, sending a bunch of Lambent Stalks up outside the tower. JACK managed to open the door and Marcus told Delta Squad to barricade the doors to prevent the Stalks from coming in by fighting past the groups of Locust guarding the elevator lobby. After breaking through, Delta Squad discovered that the elevators are unfortunately at the top and came down slow. The barricade was destroyed and the three Lambent Stalks attacked Delta Squad. Eventually, the Lambent are defeated and the group made it into the two elevators, but a Locust attack caused one elevator carrying Marcus and Anya to collapse and forcing them to climb on top of the other elevator. Upon their arrival at the top floor, Delta was attacked by Queen Myrrah atop her Tempest and they seemed to kill both by dropping a giant metal emblem of the COG on top of her. Eventually, the group reached Adam Fenix's office and defeated a Locust force outside, but had to go into the two nearby rooms and cut the power to an energy grid over the door. Delta reunited with Adam who explained that the Imulsion was alive and his knowledge of the Locust for at least five years before Emergence Day, having worked on a solution to the Lambent for twenty years. Adam gave Baird a disc that contained all of his accumulated knowledge of the Locust and Imulsion before he led them to the roof where his superweapon was located.
Battle of Pinnacle Tower
On the roof, Delta and Adam are forced to repel a Lambent attack before they could access the weapon. As Adam activated the weapon, Myrrah and her Tempest attacked and Delta fought them. Clayton Carmine arrived on a Gorasni King Raven and attempted to shoot the Tempest down, but failed and was shot down himself. After they forced the Tempest to the rooftop, Adam raised the two columns containing the Hammer of Dawn, the only weapon capable of killing the Tempest. Marcus used the Hammer on the Tempest, injuring it and causing it to retreat before it began climbing up the side of the tower. Delta fired at it's exposed back until it got shocked by the weapon and was forced to let go. Eventually, through a process of forcing the Tempest to the rooftop and frying it with the Hammer of Dawn, Delta killed the Tempest and defeated Myrrah.
End of the War
As the weapon powered up, many Lambent Stalks popped up and unleashed a wave of many Drudges, but the powering weapon unleashed an energy wave that killed them. Adam explained that that he tested the weapon by infecting himself with Imulsion and due to it's prevalence inside his body, Adam was killed by the weapon and disintegrated. As Delta grieved, Myrrah emerged from the Tempest's remains alive, but slightly injured and mocked Adam's death and his tendency to build weapons that killed many. Marcus ordered Delta not to fire and she mocked his refusal to harm her, but he instead got in close and stabbed Myrrah in the heart with Dominic Santiago's commando knife, killing her.
The weapon activated and enveloped all of Sera, killing all of the Locust and Lambent and destroying all Imulsion, ending the Locust War and Lambent Pandemic. Carmine survived the Raven crash and he helped his wounded pilot aboard the King Raven that landed on the beach next to them. Peace finally settled on Sera as the survivors of the war celebrated their victory at last.
- Gears of War 3, Act 5