Gigan

Monster of Steel" Gigan is a notorious traitor to King Desha's army. He was imprisoned in the Underworld until being freed by Miranjo.

Gigan has pledged his loyalty to Bojji and, after an altercation, has been forcibly recruited into the Order of the Underworld by King Desha, absolving him of his past crime.

(Source: Ousama Ranking Wiki)