The biting cold wind howled at their backs, while the stench of rot and decay filled their nostrils.
Looking at the enormous hole Calyrex had blasted open with Star Shower, Su Hao answered in acknowledgment, patted Miraidon beneath him, and, with Diancie and Little Hoopa in its arms behind him, plunged resolutely into the World Tree's inner space.
--It was time to settle this.
The negative-energy tentacles thrashing outside were merely a self-defense mechanism controlled by Star Creation, the Dark Matter core. Perhaps because it had fused with most of the World Tree's roots and trunk, they had taken on a form resembling plant roots.
But Reshiram and the others were responsible for suppressing those things.
Su Hao's sole objective was the World Tree's terminal: the core crystal that coordinated its internal ecosystem.
Before Star Creation completely seized control of the World Tree and detonated its roots, throwing the world's stability into turmoil once more, he and Diancie had to purify it first.
But how vast was the World Tree's inner space?
The differences between worlds had also altered the World Tree's overall internal structure.
The route experience Su Hao knew, the path leading through the World Tree to the Pokémon world, was clearly useless here.
Within the passages rolled a creeping malice, similar to the corrupted land of the final boss called "Calamity Ganon" from a console game Su Hao had played before crossing over.
The longer they lingered, the more easily they would be surrounded from within and without, then swallowed whole.
Although Diancie's Radiant Aura was the natural bane of these things, expending precious power merely to resist creatures that could multiply endlessly as long as they absorbed negative emotions was clearly not worthwhile.
Thus, Diancie only maintained the smallest possible range of Radiant Aura around itself,