Captain Marvel was at Captain America's side as they attended the meeting of the Galactic Council who decided to allow Thanos to join in the battle against the Builders. Danvers served as the communications liaison between the Kree and the Avengers when a group of Alephs made landfall on Hala.
Later on, Captain Marvel was part of a small strike-force that was teleported to the main Builder ship by Manifold in order to attack them before they were able to regroup. After a long engagement, Captain Marvel and Thor were backed into a corner by a group of Builders.
They were saved by Thanos who used Captain America's shield to refract the energy attack launched by one of the Builders. Thanos explained to them that Rogers had perished as they defeated the last contingent of Builders' on the command deck. Believing his story, Captain Marvel and the rest of the Avengers assembled on Earth with Thanos taking over leadership of the group.