Dyack creates interesting and unique universes. The world he established in Legacy of Kain sustained four sequels, most of which spin around and explore the events of his first game through time-travel. The initial story he and his team created was so in-depth, it enabled exploration in many games.
Eternal Darkness was also a fascinating universe, of buried cities, faceted gods, a eternal Roman Centurion, firefighters exploring buried temples, Lovecraftian horrors breeding in wars, and a powerless God battling three mighty deities. Though its influences are apparent, they are so tidily weaved together with a couple of twists to produce something pretty unique to the medium.
In each game, Crystal Dynamics and Nintendo respectively helped Silicon Knights achieve their vision, an achievement the studio sometimes unfortunately seems to miss when tackling a project alone. With the right supervision and support, an Eternal Darkness II fuelled with the same dark imagination that spawned its predecessor and Legacy of Kain, could be damn remarkable.
Retro would be an interesting partnership, certainly. Retro have showed us in their Metroid and Donkey Kong efforts, that they absolutely nail gameplay, mechanics, balance, control and produce work of outstanding quality. If they were supporting Dyack and co in realising their vision for Eternal Darkness 2, I'd have confidence in the project.