Gilgamesh_Official
How about using the Battle of New York as a political stunt? Have MC not participate in it and declare his kingdom a month or so before the events of Avengers and that only countries that become vassals of his will be protected by his power. Make him a world power and then have SHEILD call him for help. Once that happens have mc easily neutralize the nuke and send one of his own in the portal instead as a show of power. Give him the same status as Wakanda after the events of Black Panther as a world leader and have him make an alliance with Wakanda, sharing technology and knowledge and him using the Black Panther as a training partner for hand-to-hand combat.