In a hidden Inhuman city, Thane was known as The Healer. Thane's true nature was revealed when Black Bolt activated the Terrigen Bomb during his fight with Thanos, leading to wide-spread mutations across Earth. As this happened however, his people were killed in the process due to his powers.
Thane was created by Jonathan Hickman and Mike Deodato Jr. in New Avengers #10, as part of the Infinity crossover event.
Major Story Arcs
After his powers were awakened by the Terrigen Bomb, Thane, who had spent his life healing others, looked in horror as his new power had killed all he knew. He was found by Ebony Maw, who quickly manipulated and trapped Thane, who is the last remaining offspring of Thanos.
As Thanos was finally going to kill his last child, the Avengers arrived on the scene. Ebony Maw continued to talk to Thane about his power and destiny. He released Thane to see if he would save the world, in doing so become his father's son and take life. Thane accepted and put Thanos in a state of 'living death.'
The Black Vortex
He left the Earth with Ebony Maw, still under his manipulation.
Powers & Abilities
Thane's left hand has the ability to instantly change the very economics of existence. He lacks control of his power, thus everyone within a certain radius of him is killed.
Thane's right hand projects an amber construct which traps everyone within a certain radius of him and leaves them in a state of "living death."
Black Vortex Empowerment:
As a result of the cosmic power of the corrupting Black Vortex, Thane's cosmic potential was unleashed, vastly improving on all of his previous abilities and bestowing additional ones. He has used his cosmically enhanced power to encase the entirety of Spartax in his amber construct.
He was given a containment suit by Ebony Maw, which alters his powers so they can only be utilized through direct contact.
Unless he has the containment suit by Ebony Maw on, his powers are unstable, which unfortunately results in people getting hurt or killed.
As part of the Special Ops assignment, Infinity (13), a character by the name (Modern) Thane teams up with your agent for a Mini-Boss battle in Mission 3 - The Search for Thane.
"The hunt is on for the mysterious Thane. Whoever he is, Thanos wants him... which means we have to do everything in our power to keep Thane out of his hands." - Avengers Alliance