Because this day can't pass without one evil cosmic uber being showing up.

[thedreadflamehead]

YES! My masterplan worked! All those heroic fools were too busy worrying about the "apocalypse" or were trying to stop that Majora brat and her moon that I was using as my distractions to even notice me materialize in this realm. It was worth manipulating that primativie Earth culture all those centuries ago. Now I, the Dread Dormammu, ruler of the Dark Dimension have access to this gateway of over a hundred million dimensions which will soon all be mine as well! And best of all, that accursed Strange and his friends aren't around to stop me this time!