–Art3mis, after Sorrento unleashes the mech.
- Durability: Being one of the largest mechs available in the game, Mechagodzilla has extreme durability. This was shown when Gundam was able to cut into Mechagodzilla with his Beam Saber, yet the latter shrugged off the damage.
- Atomic Breath: Unlike other incarnations of the character, this version of Mechagodzilla possesses the ability to fire an Atomic Breath attack. It is similar in appearance to the MonsterVerse Godzilla's Atomic Breath in Godzilla (2014). Whenever the mech is about to fire its Atomic Breath, its dorsal plates glow a blue color, much like Godzilla.
- Finger Missiles: Mechagodzilla possesses Finger Missiles that can be fired at an opponent, much like the Showa Mechagodzilla.
Kiryu is piloted by Nolan Sorrento at the Battle of Castle Anorak.
Mechagodzilla is summoned onto the battlefield, where Aech (piloting The Iron Giant) charged at Sorrento's mech, firing at it with the Giant's Arm Cannon. This attack, however, proved ineffective when Mechagodzilla punched the gunter mech to the ground and blasting her in the back with its Atomic Breath. Then it noticed the Lorean that Parzival and Art3mis were in and smacked the vehicle with its tail. As it comes close to zeroing the two out by crushing them, Daito, piloting Gundam, flew in and intercepted the attack. After a brief but intense battle, Daito changed back to his normal avatar, still gripping onto the massive mech. Mechagodzilla then grabbed the small avatar, and after he shouted "FIRST TO THE EGG!" and flipping the mech off, it incinerated him with a small blast of its Atomic Breath. It then saw Parzival and Shoto running to Castle Anorak. It was close to zeroing them out again, this time with its Finger Missiles, until Aech interrupted the attack, causing the missiles to fly out in random directions. After a brief struggle, Aech held Mechagodzilla still, and Art3mis in shooting distance with an M41A Pulse Rifle. She then proceeded to shoot out Mechagodzilla's left optic, revealing Sorrento inside. After Sorrento muttered "Shit. It's her.", she then threw a bomb inside the cockpit. The following detonation proceeded to explode the head of Mechagodzilla and zeroed out Sorrento who soon respawned.
- This design of Mechagodzilla is modeled after the designs of the 1974 Mechagodzilla, 2002's Kiryu, and the MonsterVerse Godzilla from Legendary Pictures' 2014 film.
- While cited as one of the largest mechs in the OASIS, upon its introduction in 2011, this incarnation is the smallest Mechagodzilla in pop culture.
- The Atomic Breath is a reference to the mech's biological counterpart, Godzilla.
- While in the novel of Ready Player One Mechagodzilla fights against Ultraman, in the film (due to licensing issues) the kaiju fights against the Iron Giant and the RX-78-2 Gundam instead.