Why does The Depths affect Pyke and Nautilus in a different way?

A look at Nautilus' new lore makes me think that what transformed him was "The Depths" itself, the same thing that bonded with the soul of Pyke and made him a drowned undead

"It was clear the captain was obsessed with a specific wreck, one shrouded in darkness even on a fair day. The diving armor could withstand the pressures of the ocean floor far longer than any man, long enough to collect what was hidden in the abnormal murk."

"Then something reached out from the depths. He was being pulled down, and for the first time Nautilus felt liquid fear wrap itself around his heart. It was not treasure his captain sought, but some slumbering, eldritch power. "

"Nautilus screamed within the suit, but none could hear him. He tumbled back into the inky maelstrom, clutching the sinking anchor in desperation. Dark tendrils enveloped him, and he could only watch as the dimming outline of his ship faded away. Then everything went black. "

This also present some questions, as while Naut can roam freely doing what he wishes to do, punishing those that do not pay the tithe, Pyke seems to be under contract with a seemingly sentient power that orders him around.

Even when both seem to be corrupted by what's at the bottom of the ocean, they have different situations, the only motive i could think of is that Nautilus was granted freedom because he himself unwillingly freed The Depths, trapped by Nagakabouros down there, while Pyke was revived to serve this new dark god.

I guess Pyke's Bio will allow us to reach the deepest parts of this mistery