Battle of the Phoenix Burns

The final battle of the Phoenix-Fire War was decided in what is now known as the Gronian Drylands. During the battle, the Imperial legions and mages used the Blade of Shifting Chance to greatly weaken the legendary phoenix Etros and subsequently defeat and ultimately kill her.
During Etros' final stand, the bearer of the Blade of Shifting Chance was killed. While the phoenix too died in the exchange, the blade itself was never found and is missing to this day.