They struck up a friendship – something that had never happened before – and the two scoured the galaxy together. As punishment, Galactus stripped Morg of his Power Cosmic, and the other heralds finally defeated him.
Nova grew reluctant to serve Galactus after this, and he grew tired of her. The Silver Surfer entombed Nova's body in a star.

When he finally does, Galactus offers the knowledge he sought in exchange for becoming his newest Herald. Shortly after Galactus took Gabriel Lan and made him into Air-Walker, his best buddy in the Nova Corps, Pyreus Kril makes it his life mission to track down Galactus and learn what happened. When Galactus gave up trying to recruit The Silver Surfer, he began searching for a new replacement. Galactus gave her a portion of the power cosmic, enhancing her already awesome powers, and Nova was now herald to the World Devourer. Nova didn’t think anything of leading Galactus to inhabited planets until the Silver Surfer taught her that all life is precious. Mantis is a fictional superhero appearing in American comic books published by Marvel Comics.The character has been a member of the Avengers and the Guardians of the Galaxy.. The character was ranked 99th in Comics Buyer's Guide ' s "100 Sexiest Women in Comics" list. Slowly turning away from her master’s influence, Nova was dismissed, and Galactus took on a new herald. During the battle, Morg slew Nova with a blast of energy through her chest. Pom Klementieff portrays the character in the Marvel Cinematic Universe films Guardians of the Galaxy Vol. The Silver Surfer entombed Nova's body in a star.

Nova then joined with her fellow heralds – the Silver Surfer, Terrax, Firelord and Air-Walker – in opposing Morg. Galactus finally cast her out, taking the vicious executioner Morg as his new herald. The new Herald came in the form of Gabriel Lan – a member of the Nova Corps.