Following the Raszageth encounter in the Vault of the Incarnates raid, a special cinematic plays. Spoilers ahead.
Vault of the Incarnates GuidesRaszageth Fight Overview
Raszageth lies defeated, but it’s too late. The first prison of her Primal Incarnate siblings shatters, and Vyranoth, the Frozenheart, breaks free. The second prison shatters, releasing Fyrakk, the Blazing. Finally, Iridikron, the Stonescaled, who Alexstrasza feared most, is freed.