The Extermination War, also called the Extinction War, was an event where an army of lower angels under the command of the Archangel Gabriel claimed possession of unwilling human bodies and then launched a war to wipe out all of humanity. Gabriel held humanity responsible for God's disappearance and rallied the lower angels in his cause to defeat them
On the Christmas of 2016, Gabriel, grief stricken over his fathers leaving, broke open the seventh seal, which cast all of the Angels out of Heaven, and closed the gates. Gabriel led the lower angels to invade the earth, stealing the bodies of humans. Over the next seventeen years, more than six billion lives were lost and many of the great cities were either reduced to rubble or deserted. In the Battle of Shanghai alone, 200 million lives were lost. The 2018 Assault on the Eastern Seaboard wiped out every metropolitan center between Boston and Charleston. Communications with Europe were lost in 2022, Russia and the rest of Asia the year after.
On the brink of extermination, humankind rallied in what was once the upper northeast United States. All able-bodied survivors were organized under the leadership of General Edward Riesen. Seeing his chance, Gabriel massed the remaining eight-balls and set out to end mankind.
After almost two decades of war, fighting devolved into a series of violent land battles. Following a long Fabian retreat into southwest deserts, General Riesen executed an envelopment of the massed angel army at the Battle of Hoover Dam. Human losses were severe, but General Riesen had ended Gabriel's ability to wage large scale war.