Five endings that changed the course of the Marvel mythos.
Like every other event series, CIVIL WAR #7 featured the final clash between the two opposing sides--except unlike most events, both sides consisted of super heroes! With the collateral damage rising, Captain America realized that the only way to spare more civilians would be to surrender and give up his rebellion. With Cap in handcuffs, the war ended and Tony Stark rose to power as the Director of S.H.I.E.L.D.--a position he'd hold until an event we'll get to shortly.
The righteous return of Marvel's cosmic heroes concluded in this knockdown drag-out fight between Nova and the mad Annihilus. With Annihilus defeated, and the Annihilation Wave beaten back, Nova looked upon the forever altered status quo from his hospital room and saw the beginning of a new era. With characters like Gamora and Drax pulled back into the fray and Peter Quill at his bedside, Nova had inadvertently experienced the events that would lead to the creation of a little band of heroes called the Guardians of the Galaxy.
With their invasion attempt on its last legs, the invading Skrulls fought back hard, leading to the end of Wasp's heroic life. Earth emerged victorious only after the manipulative Norman Osborn killed the Skrull queen--a feat that earned him massive public approval and allowed him to force his way into Tony Stark's position as Director of S.H.I.E.L.D. Formerly kidnapped heroes like Mockingbird, Dum Dum Dugan, Spider-Woman, and Hank Pym gladly set their feet back on Earth, but Osborn's Dark Reign had already begun.
With the cosmically powerful Phoenix Force contained completely within Cyclops' body, the Avengers and X-Men rallied together to prevent the possessed mutant from murdering the entire world the way he had Charles Xavier. To do this, Scarlet Witch and Hope Summers joined forces to dispel the Phoenix's power across the globe, thus restarting the long-dormant mutant race. With Cyclops disgraced and the X-Men still split into two factions, the ramifications of this final issue can still be felt today.
The heroes may have averted an Ultron-ruled post-apocalyptic nightmare world, but their time-traveling antics to pull their mission off ended up shattering the timestream. With gateways to other universes ripped open, the main Marvel Universe ended up losing the world-devouring threat of Galactus to the Ultimate Universe, and the mysterious Angela ended up on a collision course with Earth after emerging from places unknown!