Ob Nixilis was a warlord on an unnamed plane beset by war. He was outmaneuvered by opposing warlords, and stumbled upon an ancient demon summoning chamber. He sacrificed his last remaining soldiers to bring forth the demons and call for victory, however they saw the true desire in his heart and killed every living thing on his world. Ob Nixilis' spark ignited while he walked his dead plane, after he finally realized the futility of life and all his ambitions. After his ascension, he began conquering other planes.
Eventually, he acquired the Chain Veil but was cursed as a demon. He went to the plane of Zendikar, hoping to use its rich mana to purge the curse and restore his original form, but lost access to his spark as a result of Zendikar's powerful, chaotic mana.
To add further injury to humiliation, Nahiri, Zendikar's self-appointed protector, implanted a hedron on his forehead, stripping him of what power he still possessed, causing his wings to shrivel. When he could finally rise from the ground, the bones in his shoulders crumbled. His wings were useless and they fell off a few days later. Trapped on Zendikar, he vowed revenge on the plane and its inhabitants.
Ob Nixilis studied the hedrons for centuries. He came to know their magic better than anyone save the one who made them. And when a Planeswalker would come to his place, he would make a point of making introductions. There were dozens over the countless years. And sure enough, some arrogant child finally took his lure. The proud planeswalker struck him down and extracted the hedron to be used in a ritual to save Garruk Wildspeaker. Thus Ob Nixilis regained his strength and could regrow his wings.
Still missing his spark, he knew it was in his reach. And that the only cost to regaining it would be the complete obliteration of Zendikar. First he found the Khalni Heart on Bala Ged and tried to leech its power to reignite his spark with a small hedron network. However, he ran afoul of Nissa Revane who was fighting for Zendikar. Flush with the elemental power of Zendikar, Nissa bested Ob Nixilis, removed the Khalni Heart to safety, and escaped.
After recovering from his defeat, Ob Nixilis plotted while attempting to locate where Nissa might have gone. Upon reaching Tazeem, he discovered Battle for Zendikar. The troops of Gideon Jura were attempting to imprison the titan Ulamog within a hedron network. Ob Nixilis, gleaming with joy, slaughtered a few Kor guards and siphoned the power of the hedrons into himself, reigniting his spark. In one final act of vengeance against Zendikar, he destroyed the hedron network and awoke the slumbering Eldrazi titan Kozilek. Nissa attacked him in a fury at his actions both before at Khalni Heart and now. He retaliated out of spite, defeating her. Nixilis then mocked her, stating that if only she had left him alone to absorb Khalni Heart's power he would have left Zendikar peacefully. Now, he wanted to crush and burn her world out of pure spite. He then prepared to leave but not before ensuring that no one left Sea Gate alive. He suddenly realized that Jace was attempting to manipulate his mind to just leave. Using a pain-inducing spell he broke the telepath's concentration but Jace managed to spike his mind with just enough time to prevent Nixilis from taking his head off. However, the demon's glancing blow broke Jace's cheekbone and sent him sprawling. Before Nixilis could snap his neck, Gideon arrived and shredded one of his wings. Despite being in pain, he was impressed by Gideon and offered to have a rematch on some other plane of Gideon's choice and terms at a later date. Gideon's refusal cause him to comment that the current batch of planeswalkers are both weaker and less civilized then the pre-mending walkers like himself. Nixilis attempted to kill Gideon but was stunned and delighted at Gideon's invulnerability. As they dueled, Nixilis mocked Gideon by killing several nearby fleeing Zendikari and played mind games inquiring if Gideon's need to protect Jace was his own feelings or caused by the telepath's mental manipulation. Nixilis used that moment of doubt to close the gap. Both of them proved very evenly matched as they wrestled but the demon planeswalker's superior experience won out as he locked Gideon on the ground. Nixilis then proved that invulnerability was nothing as he proceeded to drown Gideon in the muddy waters at their feet. As Gideon finally went limp, Nixilis mocked him one final time comparing Zendikar's worth to be the same as the dirty water. Nixilis then took Gideon, Jace and Nissa prisoner, took them to a cave and tortured them. However, Chandra Nalaar showed up and freed her friends. Their concerted attack managed to scare the demon away from Zendikar, although he promised vengeance against the four.
Powers and Stats
Tier: At least Low 6-B | At least 3-A, likely higher
Name: Ob Nixilis of the Black Oath, the Fallen, Unshackled, Reignited
Origin: Magic: The Gathering
Age: At least thousands of years old.
Classification: Demon, Planeswalker, formerly human warlord.
Powers and Abilities: Superhuman Physical Characteristics, Flight in demon form, Can summon demons, Black Mana Manipulation, Mind Manipulation (resisted Jace's efforts to influence his mind and actually broke through Jace's own mental defenses), Can travel across the Multiverse via his planeswalker spark, Reality Warping via universe creation in his prime.
Attack Potency: At least Small Country level+ (Managed to incapacitate Jace, Nissa, and Gideon, requiring the three of them, along with Chandra, fighting together to drive him off.) | At least Universe level, likely higher (Oldwalkers could create their own artificial planes)
Speed: At least Massively Hypersonic (Could react to several other planeswalkers trying to attack him all at once) | Unknown, possibly Massively FTL (Killed every living thing on his home plane over several decades).
Lifting Strength: Superhuman (Matched Gideon) | Unknown, likely Universal
Striking Strength: Small Country Class | Universal
Durability: At least Small Country level (Survived a combined assault from Gideon, Jace, Nissa and Chandra) | At least Universe level
Stamina: High | Practically limitless
Range: Several meters with magic | Universal
Standard Equipment: While human, he had a suit of black armor and a sword and possessed the Chain Veil some time prior to the Mending. Currently none.
Intelligence: Extremely high. He's a student of history, religion, and anthropology, taught himself several languages, and trades witty banter with his opponents while dueling them. He is also a skilled manipulator and possesses great knowledge of the hedrons' inner workings as well as thousands of years of battle experience.
Weaknesses: Susceptible to the effects of the Chain Veil despite his godlike power. Chaotic mana environments can fragment his planeswalker spark, rendering it unusable and its power inaccessible.
Key: Neowalker (Current/Post-Mending) | Prime (Pre-Mending)