And what better way to start a new campaign than the Isle of Dread?
I do plan on changing things up a bit, and injecting a little weird into the game. After all, the module is left fairly open with regards to what's really going on - one of the best things about older modules, in my opinion. That level of openness and hackability makes it way easier to make the whole thing fit into your world, rather than modern modules where you lift encounters or basic plots and have to leave the rest.
I'll be using Blood & Treasure for the game, for a nice combo of new-school ideas and old-school charm.
For a start, let's make the Kopru more interesting AND give them a little more foreshadowing than "bad things on Taboo Island!"
They're the degenerate remnants of a Mindflayer outpost who settled the Isle millenia ago. Due to the lack of suitable brains when they first arrived, they were modified to be able to digest almost anything - however, this caused the atrophy of their psionics, their intelligence, and some strange changes to their physical form.
However, they are still intelligent enough to retain a disdain for demi-humanity, to the point of superiority complex, and retain enough psionic power to be able to charm their victims. Some have a slightly more expanded psionic repertoire, who normally gain positions of influence within their civilisation.
They still worship the old Mindflayer Gods, in more primitive forms - The Devourer of Stars, The Eidolon of the Blind, The Blind Idiot, K'Tul'U...
The Pearl at the centre of Taboo Island? A psionic amplifier artifact. It is currently nonoperational, requiring some weird and wonderful fuel source to reactivate. The Kopru have been trying human sacrifice to no avail, but continue their efforts out of stubbornness and a perverse enjoyment of subjugating the local humans. Perhaps it's a single, physical bubble of Yog-Sothoth...
Taboo Island is covered in detailed hieroglyphs and pictographs detailing their history, their connection to the Mindflayers, and some other secrets about the surrounding areas.
Some of the villagers on the surrounding islands have started to develop minor psychic abilities (as Wild Talents) due to the latent psionic energies suffusing the Isle. Some have even begun worshiping the Kopru Gods instead of their usual ancestor-worship, secretly performing dangerous and blasphemous rites in the dark places of the Isle...