Firelord is a villain from the Marvel comics, He is one of Galactus' Heralds and manifests its Cosmic Power via control of Fire.
Pyreus Kril, an officer of the Xandarian Nova Corps, saw his commander abducted by Galactus, devourer of worlds, from aboard his ship Way-Opener. Kril's commander became Air-Walker, Galactus' Herald, seeking out worlds for him to destroy. The loyal Kril followed his trail, eventually becoming Galactus' newest Herald, following Air-Walker's death. Remade as Firelord, Kril wielded the energies of a miniature sun. Firelord served with Galactus briefly, until Thor offered the Asgardian construct known as the Destroyer to Galactus as a replacement Herald.
The Avengers: Earth's Mightiest Heroes
Firelord oversaw the construction of a device at a volcano that would help Galactus comsume the Earth. He ended up fighting a group of heroes made up of Black Panther, Invisible Woman, Winter Soldier, Ant-Man and Hulk. Firelord was weakened when Invisible Woman cut off his oxygen with her forcefield and was then put out by Hulk's thunderclap and his tower was destroyed by Winter Soldier with a bazooka.