"Relocate immediately after firing a shot, as our enemy is capable of pinning down your location from a single shot."
- Olympian High Command Memorandum, #13102

A variant of Avenger Tank Mk II, armed with a 155mm gun. The engine has been moved to the front of the vehicle in order to make room in the rear for the 155mm gun, mounted in a partially-traversing turret. Atop is a twin Mk 8 30mm gun mount for close defense. The 155mm Gun Mk 9 gun could fire a shell with CEP of 10 meters at a range of 30 kilometers at a rate of 30 rounds per minute due to its autolaoder. It is equipped with an Mk 21 artillery direction radar system (the two domes atop the turret front) as well as a Mk 3 Combined Gunfire Locator, distinguished by the large "marshmallow" mounted atop its mast. This system uses a combination of the acoustic signature of enemy guns, the trajectory of a fired shell, and GPS in order to detect the location of enemy artillery for effective counter-battery fire.

It was best known for its role in the Battle for Delphi. The Olympian Army boasted about the capabilties of their defensive system, as it is heavily entrenched and the entirety, from long-range guns to machine gun bunkers, was so well concelaed that Pilotmarian reconnaissance flights could not find them. While the Pilotmarian Army's tanks could deal with machine gun and direct fire emplacements, it could not adequately deal with the long-range gun and rocket artillery. Therefore, General Burns sought a plan to detect them; when they open fire, the Mk 3 Combined Gunfire Locator would find their position, summoning gunfire onto enemy positions.

When the Pilotmarian Army advanced, the long-range guns opened up, allowing the Avenger SPGs to effectively counterbattery them. The Olympians soon developed scoot-and-shoot tactics, but this meant a decrease in their firepower and accuracy. Without support, the direct fire and machine gun bunkers were then destroyed with ease.

The Avenger SPG also was employed in a direct fire role, using direct sights to destroy enemy positions at short ranges. It also used its Mk 3 Combined Gunfire Locator to find snipers, which can be responded with a large-caliber shell or Pilotmarian sniper.

To operate, press (1) to activate the main gun, and press (2) to activate the commander's gun. Both use pitch for elevation controls and the roll controls for gun traverse.