Dagor Bragolgalad

Dagor Bragolgalad, the "Battle of Sudden Light", was the first step in Sauron's retaliation against the forces of Asgard.

This battle is subsequent to the Autocratic Remnant Wars, War of Darkness, and other major conflicts of that ilk. It is one of Sauron's most recent steps to Galactic domination, which capitalises on Asgard's complete annihilation to remove any major ethereal power which could halt the Dark Lord's expansion.

It began when Mordor's forces marshalled up their legions after marching through several caverns, using bridges and other land formations from Jotunheim, another conquered realm, to invade and genocide Asgard's population. This ruinous plan would be accomplished via destroying the gates to Odin's central city using the ram named Grond. Orc Commander Gothmog would lead the assault's main force, commanding countless legions of Wargs, Uruks, Morannon Orcs, Fellbeasts, Great Spiders, Mutant Snakes, Mumakil, Haradrim, Easterlings, dinosaurs, and far more.

Considering by now Sauron's Witch-King and the other Eight Ringwraiths were destroyed, he had to rely on a network of less powerful yet more numerous Wraiths that would provide air support and magic frontline attacks to pressure enemy ranks.

Eventually, Orc forces managed to reach Asgard's main gates, though were incurring heavy losses from Asgardian Berserkers and Archers. Before releasing Ghidorah himself, Sauron's secret weapon, he decided to soften up the forces outside with Indoraptors and other Jurassic mutant dinosaurs. Afterwards, Grond was used in another vain attempt to break Asgard's Starry Gate, but failed miserably, and Grond's operators and crew were all killed.

Thus, Sauron called upon Ghidorah, his greatest weapon and adversary of heroic things in the Omniverse, whom mopped the floor with all of Asgard's troops from Dark Elves to Berserkers. Ranged units tried peppering the massive beast with projectiles, this only worsened the situation and angered the three-headed beast, whom blasted a fateful beam of energetic lightning that eviscerated dozens of troops and caused Asgardian lines to finally break.

Sauron's allied forces like the CIS Droid Army and Fourth Reich pushed in, chasing the enemy forces into the city and beginning the Siege of Asgard.