Searching around looing for magic auras Tygar and Felix find the club and amulet (as described above) and after some careful study and scholarly discussions between themselves can soon work out their functions. Tygar looking at the body of the pirate can see that claws and biting were the main cause of death (likely a few weeks ago that would agree with what you think regarding the ropes and abandoned boat). As for the Mohrg, with its age and ancient body and the state of the clothes you think its likely that it was as ceremonial turning.

Now though the quarters and prayer level of the temple seems empty and only the pinnacle above waits...