He was captured by Borgia Industries and brainwashed by them before been augmented with their technology - resulting in him becoming a Bad-Blood.
Stone Heart was the leader, or Alpha Male, of the Dark Blade Clan. Physically, he was a very powerful Yautja and easily asserted his dominance over his brethren when in melee combat. He was also shown as been immune to sonic-based attacks.
At some point in the past, he and his clan brothers - Swift Knife and Long Spear - journeyed to Earth and to the city of Neonopolis to hunt honorable prey. Lured by the sweltering heat of summer and the promise of worthy prey thanks to raging gang wars, the three Yautja could not have expected that they were heading straight into a trap.
In the year 1930, another of their clan - Scarface - had accidentally left behind some of his technology during a hunt that had gone wrong. The technology had since been procured by Isabella Borgia and her son Hunter, who used it to create their own weapons and technology as well as their own business called Borgia Industries. They also created a race of cybernetically enhanced warriors known as the Monster Squad - who they used for hunting Yautja when they came to hunt. The trio soon came under attack by Borgia Industries, who defeated and captured the heavily injured extraterrestrial hunters.
Taken to Borgia's labs, the trio of Predators were brainwashed and augmented with Prometheus Technology to make them into biological weapons. They were kept in stasis tanks for the time being, until the time came when they were needed.
Battle at the Weather TowersEditIn the year 2030, Scarface - having been exiled for his failure - was given a chance to regain his honor by returning to Neonopolis and eliminating those who had stolen and used the Predator's technology for their own means. Scarface began by wiping out the city gangs before attacking Borgia Industries. Although captured after a battle with several waves of the Monster Squad, Scarface soon broke free and recovered his technology as well as breaking out several imprisoned Yautja in the labs.
Following the orders of Borgia Industries' computer (MOTHER), Hunter's daughter Lucretia unleashed Swift Knife, Long Spear and Stone Heart to stop him. Seeing how Scarface had forcibly used Borgia's scientists to activate the bio-metrical computer locks, MOTHER activated the weather machines to make it rain and thus prevent Scarface using his cloak - before instructing Lucretia to send Swift Knife to kill the scientists while Long Spear would distract Scarface. By doing this, Scarface would not be able to turn off the weather machines.
However, Scarface intercepted his bad-blood clan brother and fiercely attacked him. Despite been a skilled brawler and efficient with his wrist-blades and despite the long range backup from Long Spear, Swift Knife was no match for his experienced clan brother - who defeated the young blood before taking his head as a trophy. Long Spear still continued to try to kill Scarface with his long range weapons - with the aid of Borgia's security and soldiers. However, his attempts failed with Scarface disabling all but the last of the weather machines. At the last weather machine, Scarface engaged both Long Spear and Stone Heart in combat.
Long Spear fell quickly due to his lack of prowess in melee combat - with Scarface easily defeating him before While Long Spear may have great long range skills, the predator's melee combat skills were nothing compared to that of Scarface - who quickly defeated his bad-blood clan brother before taking his head as a trophy. Finally, Scarface battled Stone Heart - who proved that his melee skills were much greater. Resorting to hit-and-run melee strikes as well as using his ranged weapons, Scarface wore Stone Heart down. However, the Bad Blood fled the fight and escaped before Scarface could land a killing blow - leaving the extraterrestrial hunter to shut down the last machine and leave with Long Spear's head.
Honorable DeathEditStone Heart would later battle his clan brother once again. After Scarface had destroyed a holographic projection of New Way City and killed the wave of Monster Squad sent to stop him, he entered a replica of the old New Way church where he'd found Isabella after his battle and victory over Bruno Borgia.
Inside, however, Scarface was greeted by Stone Heart before the two warriors clashed once more. Scarface once again resorted to using his hit-and-run melee attacks and utilizing both his smart disc and plasma caster to attack Stone Heart from a distance. This time, Stone Heart possessed a Predator's invisibility cloak to make it harder for Scarface to lock onto him.
However, Stone Heart was eventually worn down and Scarface delivered a critical blow - bringing the once proud Alpha Male to his knees. As with his bad-blooded brother's before him, Stone Heart's honor was restored as Scarface ripped off his skull and spinal column - leaving the body of his clan brother in the replica of the church as he carried on his own mission to regain his honor.