The Marvel ComicsCrisis Crossover from late 2009/early 2010, following Civil War, Secret Invasion and Dark Reign.Asgard, which has always been located at Another Dimension, has been recreated in Oklahoma. Loki wants it to return to its own dimension, and convinces Norman Osborn to launch an all-out attack on the city. Norman agrees, he does not like to have a city of gods on US soil. They stage an incident similar to the one that began the Civil War, to get public acceptance for the attack. The president orders to stop it, but Norman goes on anyway... and H.A.M.M.E.R. is outlawed in the process. All the other fugitive heroes team up as well, to defend Asgard from Osborn's forces.In the end, Osborn is defeated, but the battle left many casualties and the city was destroyed in the process. The heroes that were outlawed since Civil War become legal again, the superhero registration act is repealed, and Norman Osborn is sent to prison.For the trope, see The Siege.
Provides Examples Of:
Alas, Poor Villain: The fate of Loki, who arranged everything to remove Asgard from the mortal dimension, tries to turn against the Void when things get out of hand, and dies as a result. Also for the Sentry, who claimed that the Void made him do it, before pleading the heroes to execute him. Osbourne made a similar excuse, but keeping being a Well-Intentioned Extremist.
And the Adventure Continues: Siege was the end of the Mighty Avengers comic book. The team had dispersed, and only Henry Pym and Jocasta stayed at the mansion to deal with Ultron. They get rid of him, just in time to join the battle in Asgard. And although the team had dispersed, they met by their own at the place; the final panel of the comic book shows Pym leading them to battle for the last time.
The end of the main Siege storyline, when Steve Rogers announces that he will need everyone for upcoming things, may be considered a case as well. However, it's a mere mention, with the characters standing there, and not a "charging into battle" finale.
Bat Family Crossover: Aside from the main Siege series and some one shots revolving around characters who weren't getting much page time in the main story (Such as Spider-Man and the Young Avengers), the only titles that tied into Siege were New Avengers, Mighty Avengers, Avengers: The Initiative and Thunderbolts. The Mighty Avengers ties to the event were at first tenuous at best, with the tie-in issues focusing on Ultron's attack on the Infinite Avengers Mansion at the same time as Siege takes place but leads into the Thunderbolts tie in; comparatively The Initiative focused on some of Osborn's more sane allies like Taskmaster realizing the plan had gone completely off rails and the Avengers Resistance mounting an attack on Camp H.A.M.M.E.R to keep the cavalry at bay, and New Avengers provided the lead-up to the Avengers heading to Asgard, with the later issues serving the same purpose as the one-shots by focusing on Hawkeye and Mockingbird.
Hollywood Tactics: Instead of sending in the Sentry to destroy the city or using their superior technology to fight from a distance Osborn and HAMMER fought up close and personal giving Asgardians the edge. Justified in Osborn wanted a big, bloody battle to try and solidify his power base and he has Ares, God War plan the attack. Ares had previously stated he leaves the thinking side of war to Athena while he focuses on bloody and glorious battles.
The true Manipulative Bastard, however, was Loki, who was pushing Norman's buttons for months and is the one who gives Norman the idea for the attack and the inciting incident. And later we learn that the entire event was only the starting point of his master plan.
Prophecy Twist: The previous day, one of the Asgardians told Tyr, the Asgardian god of war, that Ragnarok is coming, and that the god of war will die. "Ragnarok" was actually Thor's cyborg clone, and the god of war that would die was Ares, from another pantheon)
Villain Decay: Count Nefaria, who previously was shown to be powerful enough to outfight the entire Avengers roster during their prime (including Iron Man, Captain America, Scarlet Witch, Quicksilver, Yellowjacket, Black Panther, Wonder Man, Thor, and Vision) literally single-handedly, is laid out by Wolverine and Ms. Marvel in three pages because he isn't an A-list villain. Partially justified, in that the New Avengers specifically planned out the quickest and most effective way to take him down, whilst he had no idea of the ambush.