In Knife of Dunwall when using Void Gaze and looking towards a Rune or Bone Charm, what is the symbol on Dauds hand, and why is it different from the Outsiders mark?
1 Answer
The symbol is not different, it is, indeed, his Outsider's mark.
Here's a screenshot I just took of Daud's mark in the situation you described:
If we look closely, we can see this is indeed his Outsider's mark.
Outsider's mark provided above for comparison.