Chromia is the commander of New Kalis, a task to which she is suited by her concern for those under her command.
Grimlock and Swoop spoke with Chromia while they visited New Kalis. When Cybertron was struck by planetwide earthquakes, she directed the city's inhabitants to get to cover, and later worked with Grimlock to lead them out from the devastation. However, she was forced to flee along with the others when Grimlock drove them all away from an Energon pool uncovered by the cataclysm. Though she had trouble accepting the fact that New Kalis was lost forever, Chromia was able to lead the survivors to the surface through a tunnel discovered by Swoop.
On the surface, they rendezvoused with Grimlock, who suggested it'd be safest if they stayed there. Chromia, however, insisted that since they didn't know what was out there, they should stick together. In light of an Autobot signal they received from Kaon, Chromia believed they should head for that city, but Grimlock asserted his authority, insisting everyone stay put. When a squad of Forged turned up to fight, Chromia took cover with the other survivors.
The survivors, presumably including Chromia, eventually made it to Kaon.