A Battle Between Gods!

Every Pranic Beast needs to achieve certain conditions to enter the Mystic Grade. These conditions were inherently related to their Primary Nature.

Empyrean Boars had the Primary Nature of Voracious Nature, using which they could gain the Primary Nature of any existence they consume. Thereby, to enter the Mystic Grade, they had to devour all their brethren and then be hit by a Bolt of Transcendence upon activating all the stored Nature of Voracious Nature.

The Empyrean Snappers, with the Primary Nature of Subtle Terrain Domination could control all terrain. However, they were incapable of controlling the Sandy-Grey Void. The moment an Empyrean Snapper successfully controls the grey sand similar to how it controls all terrain, it would enter the Mystic Grade. Perfect control over all terrain, irrespective of what it was. That was the condition for an Empyrean Snapper to enter the Mystic Grade.