This year is all about the events that unfold in Captain America: Civil War. There's a terrorist attack on Lagos that results in the deaths of 26 people — 11 die after Scarlet Witch moves too close to a nearby building while trying to contain an explosion and accidentally destroys it.
The Avengers face the Sokovia Accords, which is an attempt to manage them. During the ratification in Vienna, there's a bombing, and the team splits into two factions that eventually battle.
Cap and Iron Man later have a showdown in Siberia, where the latter learns about how Bucky Barnes, Cap's friend, was involved in his parents' deaths.
T'Challa then defeats Zemo, the terrorist obsessed with breaking up the Avengers.
In Black Panther, T'Challa becomes the King of Wakanda following his father's death during the Vienna bombing but gets dethroned by Killmonger. He then becomes king once more after defeating his long-lost cousin in another fight.