Death

Death was born on Earth thousands of years ago on the mutant island of Okkara. He was the son of the mutant leaders Apocalypse and Genesis, and became the first mutant to join the order of the Horsemen of Apocalypse.

An army of demons from the dimension of Amenth, led by their dark god Annihilation, invaded Earth and laid siege to Okkara. Wielding the Twilight Blade, Annihilation fractured Okkara into two halves - Arakko and Krakoa. Apocalypse, Genesis and the Horsemen managed to push back the Amenthi invasion, but at great cost - Arakko, Genesis and the Horsemen were sealed away in Amenth's dimension, while Apocalypse and Krakoa were left behind on Earth.

Stranded in Amenth, Death, his siblings and their mother defended the mutants of Arakko and held back Annihilation's armies for thousands of years, until it became clear that their resistance would soon break. When Genesis was forced to become the new host of Annihilation, Okkara fell under Amenth's control and Death and his siblings became generals in Amenth's armies.

Death and his siblings led the Amenthi invasion of Otherworld, razing the kingdom of Dryador and annexing its lands into Arakko. They marched to the Citadel and declared their intent to find a path to Krakoa and claim it for themselves, but were stopped by Saturnyne, who organized a tournament of swordsmen between Krakoa and Arakko to settle the issue.

Death, wielding the Black Bone of Amdaut, faced Storm, who wielded the Wakandan sword Skybreaker. Their fight took place in the vampiric kingdom of Sevalith, and ended in Death's defeat when Storm reflected his death gaze back at him and then drove her sword into his heart. Death was swarmed by a horde of ravenous vampires and left for dead. The tournament ended with Annihilation's defeat, the reunion of Arakko and Krakoa, and Apocalypse deciding to remain in Amenth with his wife and children. Death may have been presumed dead by his family, but was revealed to be still alive in Sevalith and possibly now in the service of Sevalith's vampiric rulers.

Powers

The Eyes of Death: Death's mutant ability is called the Eyes of Death; merely with eye contact, he is able to make anyone he looks at rapidly decay and perish. He wears a helm shaped like the head of the god Anubis to keep this ability in check. He is notably not immune to his own power, as it can be used against him by forcing him to see the reflection of his own eyes. This hurts him, but does not kill him.

Regeneration: Death possesses some level of self-healing, as he was shown to be still alive after being stabbed through the heart by a vibranium sword and mauled by a horde of vampires.

Immortality: Death is likely immortal, or at least extremely long-lived, as he is thousands of years old.