The island faded around him. Atlas definitely feared for his life for a moment there. It looked like he was going to die inside the Sovereign Sand Worm's body if he wasn't suffocated by the sand.
But, the trial was only to kill the sand worm. Escaping was not in the criteria.
The sand disappeared and the Sovereign Sand Worm did too. Its blood and guts were removed from Atlas' person as if they never existed, and suddenly, he was back in the original chamber.
"Haa…haa…haa…"
He breathed deeply as he celebrated his ability to actually do so.
'It almost feels like an illusion formation, but it cannot be one. That environment is too real for it to be a mere illusion.
Atlas was already on the road to being sucked into his thoughts again, but the pagoda ensured that he would keep his attention in the right place.
When the trial space faded away and Atlas found himself returned to the second layer of the pagoda, he was no longer there alone.