Shepard uses the power of disco to destroy The Reapers, only for a massive army of lolcats to invade from Dimension Z and destroy Earth with their Sooper Walrus Cannon(TM), causing a massive rift in space and time that destroys the SWC(TM), forcing them to engage in a massive battle with the fleet Shepard created during the game, creating a diversion for The RAF to invade through the space/time rift, damaging The Normandy and stealing all of their cupcakes and biscuits. This enrages Garrus, who uses The Normandy's super cannon to destroy The Millenium Falcon, which appeared out of nowhere, only it instead hit The Death Star, which appeared a second later, taking the brunt of the shot and splitting into five.
This causes Napoleon to engage in a final battle with his heroes, Hannibal and Alexander The Great, for control of Proxima Centauri, which has a planet with massive quantites of Iytuives ore, which contains Element -1 and Element 578. The confusion and massive destruction and loss awakens LazerBear, who had been hibernating in Canada for a hundred years (Canada survivng the destruction of Earth alongside Europe and Singapore, since they are all awesome), who promptly uses his patented Lazer(TM) to destroy the lolcat fleet and defeat Hannibal, allowing Alexander The Great to outflank Napoleon, saving the galaxy from the effects of failed invasions of Russia.
Shepard's fleet, with barely any ships left, rounds up all the sentient beings of the galaxy, stores away the last bits of Earth left, and follows LazerBear's lead to the Galaxy M-7868582478572875875 to start anew. The Milky Way begins to merge with Andromeda as the newly cristened Ark Fleet escapes.
Credits roll, and then this video plays:
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