The newest chapter of Doomsday Clock shows us what happens when the most powerful character in the Watchmen universe goes up against the combined might of the Justice League.
Warning: this article contains spoilers for Doomsday Clock #9!
In the previous issue of the series, Firestorm was framed for a massive explosion in Russia, one which killed numerous civilians and left even Superman himself comatose. The Justice League track the source of that energy burst to Mars. Many of Earth’s most powerful heroes, including several Justice League squads and most of the planet’s Green Lanterns, converge on the planet and the unknown enemy awaiting them.
Source: IGN.com Can Watchmen's Doctor Manhattan Defeat the Entire Justice League?