It appears that Ob Nixilis is now completely unshackled.
Arena of the Planeswalkers: Battle for Zendikar. The expansion unlocks two new Planeswalkers - Kiora and Ob Nixilis - and new spells and squads for these characters.
Kiora is the first character in the game to draw upon two colors of mana.
Ob Nixilis has regained his power by "by manipulating desperate native populations" and his quest will not end "until he sees Zendikar reduced to dust."
Arena of the Planeswalkers: Battle for Zendikar is scheduled to be released in January 2016.