In the crossover Green Lantern vs the Silver Surfer, the Marvel Universe villain Thanos attempts to use the rift created by Oa's destruction to unmake the multiverse, after tricking Kyle into powering his equipment with his ring. Thanos is confronted by Parallax and their powers are drained by Kyle and the Surfer, apparently destroying the rift. During the Circle of Fire event, what remains of the planet served as a base of operations for the villain Oblivion. The planet is reformed sometime later by Jordan's old friend and associate Tom "Pie-Face" Kalmaku in the graphic novel Legacy: The Last Will and Testament of Hal Jordan. The Central Power Battery is later recharged and the Guardians resurrected shortly thereafter by Kyle Rayner after he spends some time as the near-omnipotent "Ion", Kyle sacrificing his power to restore the Guardians rather than risk becoming as dangerous as Hal-as-Parallax. After attacks by Superboy-Prime and the Spider Guild, the Guardians fortify Oa by creating a planetwide armor and defensive system to prevent attacks. The full capability of the new systems is still unknown. They were not, however, enough to prevent an assault by the Sinestro Corps, which resulted in the deaths of many Green Lanterns. Afterward, the Corps doubled its defenses. However, a rogue Guardian, Scar, weakened its defenses for an attack from the Black Lantern Corps. After Sinestro killed the Guardians for their "Third Army" plot and their part in Korugar's destruction by the First Lantern Volthoom—although he spared and exiled both Ganthet and Sayd—Hal Jordan became the new leader of the Green Lantern Corps. Shortly after this, the planet was attacked and destroyed by Relic. The Green Lanterns' new base of operations following the destruction of Oa became Mogo. Following the rebirth of the Guardians of the Universe and the Hal Jordan's victory over Hank Henshaw, it was revealed by Ganthet that the Guardians were rebuilding Oa in secret with the plans to restore it to what it once was, which is now referred to as "New Oa". Legion of Super-Heroes It is revealed in Final Crisis: Legion of 3 Worlds that Sodam Yat is the last Guardian of the Universe in the 31st century, while Rond Vidar is the last remaining Green Lantern until he is killed by Superboy-Prime's Legion of Super-Villains. Oa lies mostly in ruins, the power battery cracked, and the rings of the Corps lie in a pile,