With Black Panther having assembled and then quit the Illuminati, the war between the Avengers and X-Men, and Namor's decimation of Wakanda, perhaps the last thing you'd expect to bring the pair back together is being co-members of the new Illuminati. Nonetheless, that's exactly what happens just a few months later, when the ongoing "New Avengers" series reveals a threat so dire that Black Panther puts his rage aside, offers a temporary peace between Wakanda and Atlantis, and reforms the Illuminati — Namor included.
The threat is made clear by Mister Fantastic in "New Avengers" #2. Due to a cataclysmic event in another universe, the multiverse is contracting, forcing neighboring universes together, resulting in the destruction of both. Moreover, every union — or "incursion" — accelerates the contraction, meaning sooner or later, all realities are doomed. As T'Challa himself describes the threat and his reformation of the Illuminati, "This — it is beyond me or any single one of us. So here we are, an unholy alliance that just might be Earth's only hope."
Perhaps the most telling moment in the history of Namor and Black Panther's relationship is an aside the two share during this period. Even when staring down the destruction of every known reality, T'Challa tells Namor, "When this is done — when my wants have replaced my needs... I'm going to kill you."
