Will.
Will was a devastating force—an answer to everything Northern had wondered about. He hadn't known much about it before, but he'd always suspected there was something that amplified a Drifter's power.
A true Drifter—Paragon and above, he believed. Raizel's last message had given him a clear answer to that silent question.
Raizel had also explained, while he was still alive, how a Monster's will could influence the world around it. How much it was in their nature to connect with their environment.
Back then, they had only faced a Behemoth. Yet it had stirred the ocean into a storm through sheer Will alone. Now that Northern understood the essence of Will more deeply, he was tempted to call that a soul world.
But it wasn't. A soul world would work the same for a monster as it did for a human—only more sinister and far more powerful.