So, as it turns out Troy Baker is in fact Todd Stashwick's replacement. That for starters only solidifies the theory that this 'big brother' of Nate's is to be a villain, and more interestingly enough that Baker of course wasn't originally intended for the character! Adds some credence to the comments saying his voice doesn't match the face, though that also makes me wonder if they altered the character's appearance in any way for the sake of Troy.

There's the original teaser trailer with Stashwick's voice over. So... 15 years?? Buried alive?? One would assume he's referring to Drake in all this? Though I imagine this event is perhaps set before Uncharted 4 and Baker's character is now holding that over Nate's head to force him to help him with this score he's doing. Until he ultimately betrays him that is.