The Undead Tribe used the simplest method to climb the mountain: they had enough numbers to support a simultaneous start of a mountain climbing event.
Amidst the sarcasm of 'Snow Cloud Peak', relying on their brute-force style, they finally made their way to the top layer of Bone Mountain... This mountain peak can now be renamed to Stone Mountain... Not only did they leave shiny remains all over the mountain, but the Undead Tribe also managed to convert the areas they passed through into thick stone.
Hill estimates this is the aftermath of encountering the Purple Worm... The Purple Worm is one thing, but most of the Undead Tribe wouldn't feel anything towards such a monster... Even to those small girls who tend to make a fuss, ugliness and ferocity have never really been an issue. Screaming has never stopped them from their fierce spells.
But disgusting creatures are different... This tests not the nerves but the stomach.
