From The Ashes: RWBY X Male Godzilla Reader

In a time when Atlas was testing their weaponry during their early uprising, they formulated bombs that they created with an unknown dust compound they had not researched fully, but found to be very volatile and destructive. This was also the very early time of discrimination humans held towards faunus. In hopes of testing their new weapons and sullying the faunus, the Atlas army targeted an island about 100 miles from Menagerie, where only a handful of faunus were inhabited. As a bright light scorched the earth, from the rage of the humans, a destructive monster is born. And at its core, a young faunus boy is cursed with destructive power.