The Purpose of the Crossing
The journey acts as a natural cycle of life and death. When Elder Dragons reach the end of their lifespans, they travel to the New World to perish. Upon dying, they release massive reserves of bioenergy, which flows into the land to nourish and sustain the New World's unique ecosystem.
Under normal circumstances, these dragons head deep into the Rotten Vale, a massive, skeletal graveyard where their bodies decompose and feed the environment.
The Disruption and Xeno'jiiva
The Hunter's Guild originally observed that the Elder Crossing occurred roughly once every 100 years
However, the frequency suddenly accelerated to once every 10 years, prompting the Guild to establish the Research Commission and deploy five successive fleets to investigate the mystery.
The investigation reveals two major anomalies causing chaos in the ecosystem:
The Lure of Xeno'jiiva: A newborn Elder Dragon “exploits the Elder Crossing for its own gain, using pheromones to cause Elder Dragons to deviate from their path to the Rotten Vale, allowing Xeno'jiiva to absorb their bio-energy” . Xeno'jiiva lured the colossal Zorah Magdaros toward the Everstream. If Zorah had died there, the resulting burst of bioenergy would have completely destroyed the New World.
The Predator Nergigante: The flagship monster Nergigante follows the migration strictly to hunt. The Research Commission deduced it “had been taking advantage of the migratory event to feed on Elder Dragons containing high yields of pure energy in their bodies.”