Gun Devil

Not much is known about the Gun Devil's personality as a whole. In its Devil form, it has not once displayed any form of communication in the entire storyline either due to the inability to do so or simply due to not having any interest in doing so, rendering it difficult to pinpoint any personality trait. However, given the cataclysmic damage and the countless lives it has taken in mere minutes, the Gun Devil can be described as being a vile and wicked entity with no regards to anything besides itself. Makima has stated it to be a merciless and evil being whose defeat would be worthy of having any wish granted to the person who could accomplish such a feat. Even when under Contract from the President of the United States, the Gun Devil has taken in it's own hands to brutally execute hundreds of innocent lives, including children, before even attempting to complete its given mission to kill Makima, furthermore showcasing it's malevolent nature. As implied alongside the Tank Devil, the Gun Devil shares a strong connection with the War Devil, who considers herself to be their "mother" and harbored serious reservations with transforming them into weapons. When Yoru calls out for help while at the mercy of the Chainsaw Devil, 28% of the Gun Devil trapped within the Soviet Union immediately responded by breaking out of its containment cell and rushing over to save her.

Full Devil Form (November 18th Attack-100%)
While never pictured in the manga, it has been stated that when the full form (100%) of the Gun Devil first appeared in the attacks of November 18th, it was depicted as having a full set of legs, feet, bones and flesh as well. Not much else is known about its full figure, however.

As a Devil, the Gun Devil possesses all of the standard devil abilities, such as the ability to make contracts with humans for a price and take over a dead human body and their consciousness, becoming a fiend. The first contract with it seen are a contract with the President of the United States in exchange for one year from the lifespan of every citizen of the United States to kill Makima. This contract has been made by twenty percent of the body of the Gun Devil. However, it was not enough to kill Makima, at the end twenty percent of the Gun Devil is defeated by Makima and possessed the corpse of Aki Hayakawa, which turned him into the Gun Fiend. Like all other fiends, the Gun Fiend's devil ability is significantly weakened, and it bears a distinct feature on its head, in this case being an enormous pistol. After being transformed into the Right Gun Gauntlet, Yoru, using the power of the Gun Devil, will make a second contract with the National Pistol Association of America: by sacrificing the index fingers of approximately 40,000 of the association's 3.5 million members, Yoru will transform the Statue of Liberty into a grotesque crowned creature holding a rifle. This creature was able to critically damage the Chainsaw Devil while presumably killing hundreds of lives from the bullet shot across the world.