The Second Holy Order Selection Tournament is an event that takes place during the first Guilty Gear game.
In 2180, five years after the end of the Crusades, the dimensional prison walls that sealed Justice unexpectedly begin to erode away. Fearing the threat would be released from her seal, The United Nations quickly decided to organize an international fighting tournament to see who was worthy of defeating Justice for good, where the winner who defeats Justice will be rewarded a prize: The victor gets to make a "single wish... any wish at all".
At the end of the tournament, Testament appears to the winner (officially, it is Sol, but this varies depending on the character played as), revealing that they hosted the tournament, as a front to revive Justice, and fights the winner, saying "All that's required is the blood of one more sacrifice!" However, they themselves are defeated, and they use their own blood as the sacrifice. Justice is freed from her prison, but promptly killed by the winner.
In Normal Mode of the game, all contestants fight Justice on the last stage, but canonically she is defeated by Sol Badguy and other Gears permanently lose their leader.