Jay-I425

Spartan G425, also known as Jay 425, was a former Spartan III who was once part of Incognito Company, and one of the Headhunters, where he was paired with his younger sister, Jayne.

Jay was part of Project Orion III Incognito, where a batch of Spartan III's were being created and were first deployed a month after Gamma Company.

He was eventually recruited into the Spartan IV program, where he was given his Generation Two MJLNOIR armor.

His main weapons of choice were the Assault Rifle and the standard magnum pistol, although he temporarily used a Boltshot when he was stranded on Installation 00.

Battle of Requiem
Jay, like many other SPARTAN's, was trapped on Requiem, however, he led Kal 338 and a small group of Marines to attack a small Covenant patrol and hijack a Phantom, allowing them to scout out a Covenant base.

The Spartan's Prayer
Jay, like all of the forces on the UNSC Spartan' Prayer, had to deal with multiple insurrectionist groups, meaning he saw plenty of action onboard the ship, making him question how secure the ship actually was.

Installation 00
Jay finally saw some action off the Spartan's Prayer  when the ship crashed on Installation 00, a year after the events of Halo Wars 2, where he, his sister, and a fellow Spartan III Incognito by the name of Kal, fought off the banished, being able to fend off Banished forces as long as they could. Later, Jay tried to contact the Spirit Of Fire, but failed due to the Banished's jamming stations.

Personality
Jay was often seen as sarcastic and occasionally impolite, so much so that it was surprising that he was even sent into the battlefield, but despite his attitude, is highly deadly in a fight, being skillful in a large amount of martial arts and a demolition expert, although he prefers to call himself a "badass". It is most likely this arrogance that could get him killed, with Jayne even saying, "You'll probably end up crashing on some Forerunner artifact and try picking a fight with the first thing you see, because that is how stubborn you are."