Grey Wolf was an Indian "medicine man". It was said his daughter was killed during her Sunrise Ceremony as his tribe was attacked by the U.S. army. Seeking revenge, Grey Wolf started a rebellion with the tribe's other survivors. The warriors under had no fear, for they had nothing to lose, and their sole purpose was to retaliate against the whites.
The rebels hailed in Apache Territory in New Mexico, until one day, bounty hunter Silas Greaves came to hunt them down. Silas managed to inflitrate the cave in which rebels were hiding. He killed many, but Grey Wolf managed to escape, alledgely by transforming into a real wolf.
Also on Silas' account, Grey Wolf was a psyker, able to telephatically project visions into his enemies.