Schrade wasn't actually destroyed by Fatalis. It was destroyed by Ancient Wyveria using a compeleted construct of Zoh Shia.
Schrade is the home of the most renown Monster Riders and among them was a Legendary Fatalis Rider. The Schrade Riders were sent to Wyveria for war but failed against contruct Dalamadur. In retaliation they sent Zoh Shia and other mons and Wyverian warriors to Schrade.
Fatalis monstie survived but cannot find his rider so he went back to Schrade only to find his home shattered.

Rate my head canon.