[Tiberius]

I am assuming cloning? This is taken from Marvel Comics Database.

"t was later revealed that Barney's body was taken by Egghead, who discovered there were faint vital signs and placed him in one of his accelerated healing chamber. When Egghead is eventually killed by Hawkeye, in a final battle with the Avengers, the chamber is lost and forgotten Baron Zemo discovers the chamber and because he holds a personal grudge against Hawkeye, he manipulates his brother to turn against his brother. Baron Zemo then enlists Hawkeye own mentor Trickshot, who was once again suffering from cancer. Zemo recruited him to train Barney to be as proficient with a bow and arrow as his brother.

When the training was completed, Trickshot was badly beaten and his cancer continued to spread. Barney then takes the dying Trickshot to Avengers Tower as a message to Hawkeye.

Sometime later while investigating his former mentor's death, Hawkeye was atrtacked by his brother, declaring himself the new Trickshot. Barney defeats his brother and takes him to Baron Zemo. Zemo had the brothers duel to the death, but Hawkeye manages to best Trickshot in battle. Before teleporting away, Zemo transfers Trickshot's funds over to the winner Hawkeye, then taunts the hero for turning his brother against him.

Later in custody, Trickshot agreed provide a bone marrow sample for transplant to save his brother's sight, but only so he could fight his brother again in the future.

Trickshot was later invited by Norman Osborn to join the second incarnation of the Dark Avengers."