V1

V1 is a Supreme Machine (most likely), left to roam the Earth after the extinction of mankind. Like other machines, it fights in Hell for its own desperate survival after blood ran out on the surface, slaying all manner of husks, demons, angels, and other machines in order to sustain itself with the blood they shed. V1 is a blue humanoid machine with a long head which bears a resemblance to a security camera. Printed on the left side of V1's head is a barcode and some unreadable characters. Eight, glowing wing-like protrusions come from its back which enable its aerial maneuverability, dashing, continuous sliding, as well as the ability to store weapons that are not in use. "V1" is displayed on the left side of its torso. V1 has the Feedbacker as its left arm, which it uses to punch and deflect projectiles.

V1 is almost identical to its successor, V2 but with a deep blue colour scheme. Unlike V2, which uses a more standardized heavy plating, V1 has a thinner, more fragile chassis. This makes it capable of repairing itself via direct contact with fresh blood.

V1 has a unique feature shared by no other machine: the ability to directly absorb blood from enemies simply by soaking it in through their armor. This is the main way to heal in ULTRAKILL, so players will need to actively hunt down enemies to obtain fresh blood. Blood absorbed is presumably used to repair its chassis and important internal organs, as noted in the death screen.

V1 has built a notorious reputation throughout its time in Hell. This reputation has grown to the point where if it enters a room, any and all entities inside will immediately attack V1, with a few exceptions

It is implied that V1 was created to fight Earthmovers, as it was the last machine to be built for the Final War and never made it to full-scale production.

V1 has no actual gender due to being a machine, but it is more masculine in nature.

The system messages on the death screen imply that V1 possesses sentience and fully functional emotions, as it possesses a limbic system and a desire for self-preservation beyond its normal programming. The line "NO VOCAL INTERFACE DETECTED, UNABLE TO COMPLETE TASK." (emulating the phrase "I have no mouth and I must scream") supports this theory as it indicates a desire to verbally express pain, while its last message of "I DON'T WANT TO DIE" after its attempt to flee combat indicates an intrinsic desire to survive.

Although V1 is a machine it does have the capability of feeling emotion, although it may struggle with this, along with finding empathy for the blood it spills from others, especially given it uses blood as fuel.