The Dark Id is Robert Coffey.
There's just something too familiar about his overall personality. Literally all that's missing is constant references to how much he hates Tyne Daly.
Partly because of their eerily similar personalities (in TDI's version of events, anyway), but mostly because they both have an evil laugh that consists of "Bwahaha!"
Id will come out of Let's Play retirement to do Drakengard 3
And then wishing he stayed in retirement.
- Somewhat Jossed. He's out of retirement, but for Fallout 1.
- Now it's CONFIRMED!
Id was secretly the writer for Drakengard 3
So much of the dialogue in the game sounds like how he'd normally write his Alternative Character Interpretations