10 Justice League Villains MORE Powerful Than Darkseid
3. Eclipso
Eclipso first appeared in 1963 as a fairly run-of-the-mill magical villain, but like many Silver Age characters, he was eventually re-evaluated and given a more dangerous origin as the incarnation of the Wrath of God. This role was taken away from him by The Spectre, when Eclipso became too focused on revenge rather than 'vengeance'.
His biggest clash with the JLA was in his own miniseries - Eclipso: The Darkness Within in 1992, when he used his powers to take control of the minds of various heroes, preying on their anger and their darker emotions. He eventually went so far as absorbing the possessed heroes within himself, growing in size and power, until the final confrontation on his moon base (during an eclipse, naturally).
Of course he was ultimately defeated, spinning off into his own series, and showing up various times throughout DC history, popping up in Brightest Day, and as recently as the Rebirth era.