This character is based on a character from "The Shadow over Innsmouth", by H.P Lovecraft. Captain Obed Marsh was a sea captain who conducted lucrative trade for years with with islanders in the south pacific acquiring gold that enriched his hometown of Innsmouth. He had discovered that these islanders themselves had been making trade with a race of fishmen below the sea offering them brides and sacrifices in exchange for their riches and adding to the Fishmen population as their offspring would begin to transform as they matured from looking human to becoming another fishman. However other local tribes caught on to their neighbor's shenanigans and wipe them out!

Worried how this will effect his business Obed Marsh makes contact with a group of Fishmen himself at a reef off the coast of his home town, and offers to make trade of Sacrifices and wives in exchange for gold. This goes on for a while till the string of disappearances needed to keep this deal going catches up to Obed and he gets arrested, but without the sacrifices the fishmen get angry and storm the land killing off resisters. From there Obed takes control over the town leaning all in and becoming a cult leader as he profits off the deaths of many.

I imagine this pokemon version would be an enemy to Kaida and Polaris. He is no Pirate but a "legitimate" Sea Captain who's actual practices are worse than Kaida's, an infamous outlaw, but he remains in the good graces of society because he is a rich man making himself richer off of slaves and the blood of others. Meanwhile Polaris would be interested because she is invested in all things weird, eldritch, and otherworldly maybe seeing him as something more like a rival than an nemesis.