The most important component of the Harvest is Carol Danvers' DNA — at least, according to Gravik, who's gone to extreme lengths to get it. When he puts himself through the machine to receive the DNA, he unintentionally gives the same powers to G'iah. However, he believes he's with Nick Fury, who will die any minute from radiation poisoning, so seems to think exposing him to the serum wouldn't have any impact.
Thinking himself invincible and Fury weak and on the brink of death, Gravik finally claims his opportunity to kill Fury. But G'iah, who's already a Super-Skrull but who Gravik believed was dead, blocks his punch. The pair test out their new powers in a fight to the death. Featured most prominently are Hulk and Korg's strength, the ice of Frost Beast, Mantis' psychic empathy, and Captain Marvel's powers. The latter prove to be the strongest. We know that Gravik has the power to regenerate, but nothing can save him from a Captain Marvel-level energy beam, which leaves a gaping hole in his chest.
Since G'iah tested out the other powers in her fight against Gravik and Fury specified that Carol Danvers' DNA is a key component of the Harvest (which he guarded with his life), this finally ends the question of who the strongest Avenger is.
