Origin

As a boy, this Ghost Rider was a member of a tribe that didn't dare leave their cave and face the snowy weather. One day, a stranger with a Wendigo curse came to their cave. He quickly asserted himself as the leader of the tribe and then systematically killed all of them but this boy. This Wendigo had the same intellect mutation as the boy, so he took pity on the boy and dubbed him Ghost for surviving.

Ghost ventured into the snow to claim his vengeance. Instead, he found Mephisto, who offered him the power to take on the Wendigo. Mephisto turned the boy into the first Spirit of Vengeance, and he rode atop a mighty Mammoth. He kills the Wendigo and gets the attention of Firehair, who invites him to her Avengers.

Creation

Ghost first appeared in Marvel Legacy #1 as a member of the Avengers 1,000,000 BC, a major player in Jason Aaron's Avengers plans for Marvel's oldest heroic mantles.

Major Story Arcs

Avengers 1,000,000 BC

Ghost was approached by Firehair for her team of champions to defend the mortals of Earth against a Celestial, named Zgreb, who was simply looking for a fellow Celestial that landed on Earth before any of these Avengers were even born.

He would stay with the team for many battles including ones against: the first Moon Knight, a young Thanos, and an army combined of Frost Giants and Negative Zone insects. They would disband after Black Panther's death at the hands of the Frost Giants, only to reunite briefly when the son of Odin, Thor, was being born.

Avengers Assemble

After Thor's birth, Ghost would travel the Earth tracking and burning sin, only to see it become more and more prevalent. The last straw was when he came across a tribe of people who followed a man who convinced his tribe that he spoke to the "Great Light in the Sky" and used that to abuse them. Ghost was going to burn him, but the tribe tried to defend him. Ghost was forced to burn them all.

Depressed, he went searching for Agamotto to ask him about the future and if sin would ever end. He found the sorcerer freshly injured after a confrontation with Mephisto. It inspired Agamotto to get the team back together and meet up with the present day Avengers. Agamotto intended for them to become allies, but when he is attacked by an unseen force, his team blames The Avengers and start brawling. As the dust settles, Doom Supreme and his mutliversal Masters of Evil reveal themselves.

With the two Avenger teams fighting Masters of Evil, Doom Supreme conjures a mystical plague to kill off all the caveman as a last ditch effort to stop humanity from creating inheritors to the legacy powers. Ghost decides to ride his mammoth into the middle of the plume to burn the hottest he ever has to destroy it, reducing himself to ash in the process.

Powers

Mutant Intellect: Ghost seemingly had an intelligence that was relatively larger than most of his species.

Spirt of Vengeance: After a deal with Mephisto, Ghost was transformed into a Spirit of Vengeance. His head would burn with hellfire exposing his skull. He would be able to manipulate hellfire to empower his bone weapons and his pet mastodon. He presumably is capable of using the Penance Stare.