BIOGRAPHY - page 19
The time of great peril soon came. T'Challa and Ororo gathered at Avengers Mansion with the active teams and reserves at the request of Captain America. When Cap explained the threat they faced was the Phoenix Force, however, Storm walked out on her husband and new teammates without a backwards glance, returning to her true family with the X-Men on Utopia. [New Avengers (2nd series) #24] Indeed, Captain America explained the Avengers intended to take Hope Summers away from the X-Men and into custody, believing her to be the next host for the Phoenix Force. Cap believed the Phoenix was coming to Earth as a threat, and didn't intend to allow the two to merge. He came at the X-Men in full force, drafting every available Avenger to lay siege to Utopia. The Black Panther and Storm were forced to stand on opposite sides of the conflict, laying bare the strains to their marriage caused by T'Challa's distance and self-isolation in recent months. [Avengers vs. X-Men #2] When Hope escaped from Utopia, both teams 
organized to hunt her down at possible sites around the globe. One of the locations was Wakanda, when Black Panther and Storm came to blows again. In this match-up, T'Challa revealed he had anti-weather satellites and protocols in place specifically to defeat his wife. This betrayal only exacerbated the fight, forcing husband and wife to fight hand-to-hand. Ororo released her pent up frustrations on T'Challa, and it became clear their marriage would not survive this divide. As the X-Men cleared out of Wakanda to search for Hope elsewhere, Ororo left behind her wedding ring for T'Challa to find. [AvX: Vs #5]
The Phoenix Force eventually found Hope but, due to Tony Stark's efforts to block it, it shattered into five pieces and possessed the X-Men Cyclops, Emma Frost, Colossus, Magik and Namor the Sub-Mariner instead. These Phoenix Five went to work improving the planet for mutantkind and humanity in general. Their efforts were met with cautious optimism by the world at large, but Captain America and the Avengers remained convinced they were a threat. T'Challa walked the tightrope between continuing to support the Avengers as Black Panther and remaining neutral as King of Wakanda, like the other nations of the world.
The time came when Captain America and the Avengers kidnapped Hope from Utopia, provoking outright war between the X-Men and Avengers again. Black Panther broke from the United Nations and secretly offered support and shelter for the Avengers in Wakanda. He also assisted Tony Stark in his efforts to find a solution to the Phoenix situation. As matters grew more tense, however, Namor targeted Wakanda to draw out the Avengers, retrieve Hope and eliminate the 
Scarlet Witch, the only Avenger thus far able to cause the Phoenix Five any pain. This wasn't merely a single super-powered foe, though -- Namor brought the army of Atlantis with him, making this officially an act of war from one nation against another. T'Challa was furious at Namor's actions, and stood with the other Avengers in defense of his homeland while they evacuated to the extra-dimensional K'un-Lun. [Avengers vs. X-Men #6-8]
Nevertheless, large portions of Wakanda were flooded and destroyed by Namor's Phoenix-empowered tidal wave and the ferocity of the Avengers' counterattack. Wakanda was not conquered, but it suffered as greatly as the nation ever had in all its history before Namor was 
defeated. Namor's attack (and Illyana merging Limbo with this plane to create Hell on Earth as a prison for the captured Avengers) finally led Storm to abandon Utopia and offer aid to the Avengers. The Avengers accepted her, but T'Challa did not. Ororo had stood with the enemies of Wakanda as they lay siege to the nation, killing thousands and devastating the country. As queen, she had committed treason and was now enemy of the state. As high priest of the Panther clan, T'Challa annulled their marriage on his own authority. The Avengers and X-Men soon united and defeated the Dark Phoenix, but there would be no union of any sort between T'Challa and Ororo. Not anymore. [Avengers vs. X-Men #9-12]
After the defeat of the Phoenix Five, Storm returned to the X-Men full time and became headmistress of the Jean Grey School. Tempers cooled eventually, and she and T'Challa found time to talk. They were able to move past the anger that defined the final days of their union, but they both knew their marriage was still over, regardless. Each had such different and all-consuming responsibilities that they would never be able to truly live comfortably in the other's world. They would remain friends, perhaps even still in love, but their time together was passed. [AvX: Consequences #1, A+X #3, Wolverine and the X-Men (1st series) #24]
It was a tradition of Wakandan education that graduating students participate in a set of Games designed to test their mind, body, and spirit. T'Challa was present to congratulate the new generation of Wakanda's leaders as they solved the final riddle and learned their destiny led them to the stars. A day of joy quickly turned sour as the Black Panther and the victors faced a curious and haunting phenomenon. Within a small area of jungle, the sky turned red and another Earth became visible in the space above them. Mysterious figures crossed over from that other Earth and opened fire on the Wakandans when they were spotted. T'Challa's child pioneers were slaughtered within moments. He captured the last of the invaders, but not before she triggered a device that destroyed the second Earth, ending the red sky.
This "Black Swan" told T'Challa a tale that filled him with great dread. She wove a fable regarding these events, called Incursions, where two Earths begin to occupy the same dimensional space. Once an Incursion began, it must be resolved in eight hours. Either both Earths collide, triggering a chain reaction that would destroy the entire two universes they hail from, or one Earth is 
preemptively destroyed, ending the Incursion and sparing the second Earth and both universes. Furthermore, the loss of two universes caused the multiverse to "contract" with each Incursion, speeding the end of all things for EVERY universe, not just those directly involved with the Incursion. Foreseeing the ramifications of such a systemic multiversal problem, the Black Panther swallowed his pride and reached out to the Illuminati, the group he had denounced from the beginning and refused to join when they first formed. [New Avengers (3rd series) #1]
T'Challa's decision proved particularly difficult due to the presence of Namor among the Illuminati. Namor's attack on Wakanda during the Phoenix incident was still seen as an act of war, making the unrepentant Atlantean prince persona non grata in Wakanda. The Dora Milaje Ayo and Captain Aneka even spoke up to question T'Challa about his decision to bring Namor into the Necropolis. T'Challa informed Namor of the very strict conditions under which his presence would 
be tolerated. Namor would not speak to any Wakandan besides T'Challa. He would not leave the boundaries of the Necropolis, the only territory in Wakanda which T'Challa specifically controlled at that time. And T'Challa made it clear to Namor that, once the Incursion crisis was resolved, the Black Panther would seek vengeance for his fallen people, and he would murder the Sub-Mariner personally.
After Reed Richards interrogated the Black Swan and information regarding T'Challa's own experience was analyzed, the Illuminati decided the best course of action was to reassemble the Infinity Gauntlet, whose Gems had been in the custody of the group for many months. Although Professor Xavier was now dead, his Mind Gem had been willed to Henry McCoy, the Beast, who was also inducted into the Illuminati. As the next Incursion occurred, Captain America wielded the Infinity Gauntlet to put his plan into action. He used the power of the Gauntlet to push an entire reality back, evacuating the second Earth from their dimensional space and ending the Incursion without either world being destroyed. Unfortunately, the Gauntlet became unstable and the Infinity Gems were either shattered or lost as the Incursion ended.
In the aftermath, the Illuminati squabbled heatedly over what to do next. Captain America was adamant that they not even consider destroying other inhabited Earths to save their own, while most of the other members wanted to keep that option open as a last resort. Without the Infinity Gauntlet (which some blamed Cap for losing), there seemed to be no other options currently on the table. Cap turned to T'Challa for support, but the Black Panther put his role as a king over his 
morality as a man. The protection of his people and his country trumped all other concerns. Namor and Black Bolt felt the same about their kingdoms. In the end, Iron Man directed Doctor Strange to wipe Captain America's memory of the Illuminati, violating their friend's trust and removing him from the group he would not support. [New Avengers (3rd series) #2-3, Black Panther: World of Wakanda #2]
Weeks passed, and the Illuminati made their preparations. They reverse-engineered the Black Swan's anti-matter bomb from the recovered trigger mechanism, all the while praying they would never have to use it. Their ultimate decision was delayed over the next few Incursions. On one Earth, the Illuminati found Galactus devouring their rival Earth, leaving their world in the clear. Still the heroes, they fought as best they could against Terrax the Truly-Enlightened, Galactus's Herald, in defense of that Earth's people until the Incursion forced them back to their saved Earth. [New Avengers (3rd series) #4] They extended some trust to Black Swan, releasing her from 
confinement under the threat of an explosive necklace. She informed them the blue sky at the next Incursion site (instead of red) meant Mapmakers. Another rival faction in the "game of worlds," the Sidera Maris "mapped" the multiverse by devastating Earths, leaping from one to the next during Incursions. Confirming the second Earth was completely devoid of life, the Illuminati returned to their side of the Incursion. T'Challa was the one who activated the trigger mechanism, destroying his first Earth. [New Avengers (3rd series) #5-6]