Arthur Petrelli

Arthur Petrelli was the husband of Angela Petrelli, father of Nathan Petrelli and Peter Petrelli, grandfather of Claire Bennet, Simon Petrelli and Monty Petelli and great-grandfather of Tommy Clark and Malina.

Arthur Petrelli was an evolved human with the ability to absorb the ability of other evolved humans on contact.

History
Via a spirit walk, it is revealed that Arthur arranged Nathan's accident, which led Heidi to become paralyzed. Arthur went on to plan another attempt on Nathan's life with the aid of Linderman. Angela attempts to kill Arthur upon learning of his plans for Nathan. Arthur, bedridden has Dr. Livitz to tell Angela and his family that he is dead. Arthur appears in one of Angela's dreams of the future. In the dream, Arthur confronts Angela and forces her to be unable to move once she awakens. Meanwhile, at the Pinehearst building, Maury Parkman reports to a bedridden Arthur on the progress of Daphne Millbrook's recruitment. Knox soon brings Adam Monroe into Arthur's room and Arthur absorbs Adam's rapid cell regeneration, causing him to rapidly age and die.

Arthur, now fully healed, addresses "the bad guys" but is interrupted by the entrance of his son. Arthur tricks Peter and absorbs all of his powers, leaving him powerless. Arthur also uses his power to absorb Maya Herrera's poison emission, thus winning the trust of Mohinder Suresh, whom Arthur gives the task of completing the formula.

Just as Mohinder begins an experiment on Peter, Sylar appears, kills Dr. Livitz and releases Peter. Arthur throws some lightning at Peter but misses, leading Peter to escape. Arthur stops Mohinder from hurting Sylar and reveals that Sylar is his son. Arthur tells Sylar that Angela tried to kill him as a baby and Sylar decides to side with Arthur, telekinetically throwing Peter out of a window.

Arthur learns of Hiro's spirit walk, teleports to Africa and kills Usutu, also erasing Hiro's memories to the point where he thinks he's ten years old again.

Returning to Pinehearst, Arthur teaches Sylar how to acquire abilities empathically. Arthur also learns from Daphne that Matt Parkman is attempting to help Angela. Arthur enters Angela's mind and after a few words from his ex-wife, he releases his hold over her. Knowing that the only way to perfect the formula is with a catalyst, Arthur sends Knox and Flint after his granddaughter, whom he also believes to be the catalyst.

Arthur uses his precognition to discover that another eclipse is on its way. Upon regaining his powers after the eclipse, Arthur travels to 1991 and removes Hiro's space-time manipulation, also absorbing the catalyst from him. He then throws Hiro off a roof and sends Claire back to Primatech with a warning for Angela. After returning to Pinehearst, Arthur implants the catalyst into the formula, perfecting it. Arthur is then confronted by Peter and The Haitian. The Haitian is unable to suppress Arthur's abilities for long so Arthur attacks Peter, who shoots him. The bullet is stopped mid-air by Sylar, who asks Arthur if he's his father. Arthur answers but Sylar knows he's lying and kills him himself.

Ability Absorption
With this ability, Arthur could remove the ability of another evolved human by touching them.

As shown in Dying of the Light, Arthur gained immediate use of the gained ability, such as when he stole Adam Monroe's rapid cell regeneration, Arthur regenerated the damage to his nervous system and the hole in his throat from the tube placed there within a few seconds. Arthur could take multiple abilities at once from someone who has multiple abilities, as shown with Peter in Dying of the Light.

Physical contact is required for Arthur to absorb abilities. Arthur hugged Peter Petrelli to absorb his abilities, and Knox forced Adam's hand into Arthur's. However, skin-to-skin contact was not required, as Arthur could absorb Maya Herrera's poison emission through her hospital gown and Hiro Nakamura's space-time manipulation through his shirt in Our Father.

When Arthur stole Peter's abilities in Dying of the Light, Peter suffered no obvious ill effects, although the process appeared to cause intense pain.

As shown in Dying of the Light, Arthur doesn't absorb abilities upon contact, Knox's hand brushed against Arthur's, yet Knox retained his fear induced enhanced strength.

According to Arthur in Eris Quod Sum, the removal of abilities due to ability absorption is permanent. However, this has been proven incorrect as Matt Parkman, Jr.'s activation and deactivation partially restored Hiro's space-time manipulation, allowing him to just stop time. Hiro's space-time manipulation eventually fully returned, but due to a brain tumor Hiro developed, he didn't have full control until his tumor was removed, showing that stolen ability can be fully restored.

Due to all of the abilities Arthur absorbed as of Our Father, René was only able to block them for a few minutes before he began to manifest his abilities again.

In Our Father, Arthur seemingly uses ability absorption to take the catalyst and Hiro's space-time manipulation from Hiro Nakamura. He later transfers the catalyst into the formula.

Telepathy (absorbed)
Arthur was already an experienced user of telepathy in April 2006.

Arthur could use telepathy to read thoughts, project thoughts, control a person's behavior and personality, and alter a person's memories.

According to Daniel Linderman, lasting telepathic alterations, such as thought projection or memory erasures, to a person's mind leave "scars", but evolved humans possessing the ability of healing or regeneration can counter memory loss/mind control by healing the scars.

After being paralyzed by Angela's poison, Arthur could still communicate telepathically, which is how he talked to everyone as all he could move was his eyes until he regenerated.

Arthur was able to imprison Angela in an unresponsive trance, disguise himself as Daphne within Angela's dream to trick Matt, and inflict a psychosomatic stab wound upon Matt from inside Angela's dream.

Rapid Cell Regeneration (absorbed)
Arthur Petrelli was completely paralyzed and breathing through a tube, having suffered permanent damage to his nervous system due to Angela poisoning him. He absorbed Adam Monroe's rapid cell regeneration, killing Adam, but healing all of the damage done to his body by the poison, reversing his paralysis.

Electrokinesis (absorbed)
After stealing Peter's abilities, Arthur demonstrated his new electrokinesis by creating and holding a ball of lightning.

In Eris Quod Sum, Arthur was seen to be directing short bursts of lightning from his hands at Peter. He appeared confident in his skills as he was able to control the blasts to a level that he believed would not kill Peter, though it should be noted that his confidence could have been misplaced: none of the blasts even hit Peter.

Poison Emission (absorbed)
Arthur briefly used poison emission once he took it, but he didn't use it long enough to affect anyone.

Telekinesis (absorbed)
Despite having this ability for a relatively short amount of time, Arthur was quite adept at using telekinesis. With a mere movement of his hand, he was able to telekinetically break Maury Parkman's neck, killing him. He was also capable of suspending others in mid-air without much concentration, as shown when he immobilized Sylar in the air while he talked to Flint.

Mental Manipulation (absorbed)
Arthur used this ability to erase Hiro's memories. Arthur's intention was to erase only those memories Hiro gained on his spirit walk, but due to Ando's interruption and Arthur's preoccupation with one of Usutu's paintings of an eclipse, he mistakenly erased years worth of Hiro's memory, leaving Hiro in the mentality that he was ten years old. However, for whatever reason, Arthur did not use this to block Hiro's powers as Hiro was able to teleport away.

Space-time Manipulation (absorbed)
In It's Coming, Arthur used this ability to teleport to Africa, and then to go back to Pinehearst Headquarters. Arthur was also able to time travel to 1991, to the Charles Deveaux's rooftop, and was capable of sending Claire through time and space without teleporting himself.

Precognition (absorbed)
In It's Coming, Arthur used this ability to draw a picture of the eclipse. He later drew many other prophetic drawings in The Eclipse, Part 1, such as Claire in Noah's arms, and Sylar and Elle embracing.

Other Possible Abilities
It would make sense if Arthur absorbed all of Peter's (potentially) absorbed abilities, which would include:

Weaknesses
As shown in  Our Father, a bullet through the back of Arthur's brain was able to kill him, like it would with anyone with rapid cell regeneration.

When using telepathy in a dream and disguising himself, his shadow remains the same as his true self.

Ishi Nakamura was able to use her ability to undo the effects of Arthur's mental manipulation.

During the eclipse, Arthur was unable to use any of his abilities.