An old, ancient, crabby, tortle fisherman, has a harrowing encounter out at sea. After which he is forever marked by Slarkrethel, a stain on his soul, which gifts him his psionic powers.  
 
Now he is like a moth to a flame, seeking out knowledge to uncover some great truth or complete a special personal mission he has become obsessed with.

Steadily, through research, trial and error he has learned to shape and control his psionics and dredge up echoes imprinted on his mind that flicker and flash of a forbidden location or treasure that he must find. Perhaps he interprets it as some eldritch creature he must seek out or gateway to a veiled world he must unlock.  
 
Whatever the belief, it doesn't matter to him, he must fulfil this purpose. At which point, either his mind will be at peace... or be in pieces.  
 
"I drowned, but something else surfaced in my place." 

He has seen that this voyage will require a crew, in fact he knows this is each and everyone's "destiny" to accompany eachother. To him, he is their ferryman, and they are the precious cargo to be protected at all costs. They must be delivered to their final destination, intact.  
 
To what end he does not know. Is it to defeat some elder evil or simply to feed them to it? Is he the savior meant to prevent the world's grim fate or simply a puppet of some monster of the depths? He banishes the latter options from his mind, wishing he had never conjured the idea to begin with.  
 
The mental flashes are too unclear to tell what is in store for him. He will have to set sail into the unknown to find out the truth.