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RUMBLE!
The entire crust of the continent of Muspelheim shook, a continent so large it was almost as large as Planet Earth. In fact, within Yggdrasil, every single continent was a mega continent of immense size, as each one of them was once a Realm of its own, a self-contained world that ended merging together into what know is known as Yggdrasil.
Because of its immense size, and an even larger underground area, Muspelheim, and perhaps every continent, would take an immense amount of force to even shatter, and yet, the battle between the Venerable and Surtr was enough to even shake the crust of the mega continent, and awaken the beasts sealed underground.
