In the future, in a world similar to that of Days of Future Past, Franklin Richards and Rachel Summers had a son whom they named David. Both Franklin and Rachel perished not long after in a Sentinel attack and David was left an orphan fending for himself in a war-ravaged Earth where mutants are hunted and executed.
David Richards was created by Judd Winick and Mike McKone and first appeared in Exiles #12.
David Richards first appeared as a young child in a world ravaged by Sentinel attacks on mutants and would, according to the cosmic Timebroker, grow up to enslave the entire planet when his mutant powers manifested. The reality-hopping Exiles and Weapon X teams met the young David and Sabretooth elected to stay behind to help raise and tutor David to try and avert his destiny. Later on in the Exiles series, we see a fully grown David Richards and the result of Sabretooth's attempts to guide him.
Major Story Arcs
Another Rooster in the Henhouse
Two teams of superhumans, the Exiles and Weapon X, arrived on David Richard's reality and were given the task by the Timebroker of freeing him from a prison camp run by Sentinels. The combined forces of both groups managed to free David and several other captive children with relative ease but the Exiles and Weapon X leaders Blink and Sabretooth received further orders from the Timebroker that their real mission was to kill David to prevent him growing up to conquer the planet.
When the rest of the teams found out their mission, they debated whether or not murdering David was justified and the debate quickly turned to violence. With most of Weapon X in favor of killing David, the Exiles and Sabretooth fought against the other team intensely and Weapon X's Deadpool was killed in the skirmish.
After the fighting settled down, Sabretooth believed that all David needed in life was a strong parental role model and someone to help him deal with his unfathomable powers and his world's circumstance. Believing he could steer David away from his dark destiny, Sabretooth left Weapon X and remained to help raise and tutor David.
A Tooth for a Tooth
Sabretooth protected David for years and helped him and a small band of rebels survive against the horde of Sentinels sent to eliminate them. As he reached puberty, David Richards' mutant powers bloomed and he eagerly used them to fight back against his oppressors. Sabretooth watched as the boy who had become like a son to him, took command of an assault to destroy all the Sentinels on Earth and was mortified when he decided to finish the job by eliminating all the humans.
By chance, Blink found herself visiting David's world again at this time and was taken control of by David who wished to use her as a weapon. Sabretooth attempted to stop David but was almost instantly dwarfed and subdued by David's power. Kidnapping Blink, David set out to begin his war against all the humans on Earth.
Using Blink's ability to teleport as a means of transport, David telepathically forced Blink to teleport the two of them to an underground hideout where he had trapped several humans prior. He then forced Blink to use her powers to murder each one of the humans by disrupting their molecular mass via unorthodox teleportation (such as teleporting them into solid objects or only teleporting half of their body). Blink was unable to resist the mental commands of David and was forced to brutally and inhumanely kill every human David had captured.
David further used Blink to travel across the world and similarly butcher humans against her will. Eventually Sabretooth managed to track down David and Blink and managed to take David by surprise and torn his heart out of his chest, killing him. Blink was free from his control and racked with guilt, while Sabretooth's murder of David made him the target for several of David's followers which led to him to joining the Exiles.
Powers and Abilities
Due to his omega level mutant parents, David inherited vast psychic and psionic powers from both his parents. While the exact extent of his power was never fully seen, only speculated on, he was described as being "stronger than Professor X, Magneto and the Phoenix Force combined" and was cited as the strongest being to ever be born on Earth.
David inherits his mother's telepathy and telekinetic abilities and his father's psionic abilities. He has honed his mental powers to the point of easily being able to telepathically take control over another being and forcing them to do his will. He is incredibly proficient in using his immense powers, able to single-handedly destroy nearly a hundred sentinels while simultaneously co-ordinating an entire army's movements telepathically.
David also displayed powers which resembled those of the Phoenix Force, suggesting that, like his mother and grandmother, he has some form of bond with the Cosmic entity as well.