Given that they met in Captain America: Civil War under stressful circumstances, Ross and T’Challa might not necessarily be friendly with one another at first in Black Panther, but hopefully Ross will take after his comic book counterpart and prove himself to be a valuable ally to the hero in the end.
Martin Freeman’s Everett Ross appeared in Captain America: Civil War as the Deputy Task Force commander of the Joint Counter Terrorist Centre, and he answered to U.S. Secretary of State Thaddeus Ross.
Anyone who’s familiar with the Black Panther lore from the comics knows that Ross has history with T’Challa from his time at the State Department, eventually becoming one of the United States’ main experts on Wakanda.
However, after Helmut Zemo revealed to be the true perpetrator, Ross had no problem mocking Civil War’s main antagonist once he was imprisoned.