: I don't recall any such character from the Forerunner trilogy, or no mention
: of anything that could be a Guardian. This is definitely the character
: from the mysterious silhouette earlier in the week.

Silentium had Haruspis, who was apparently the keeper of the Domain of some sort. But it's a little underwhelming that the guardian of this super esoteric and mystical knowledge is just another big, skull-faced robot that you fight.

It seems the Promethean Soldiers talk as well. I suppose that adds a little personality to them. Wonder if they're replacing the Knights entirely.

Other than that I love the way Sanghelios looks. Finally we see Elite architecture that isn't a feudal Japan knockoff and actually looks like it was built by a millennia-old spacefaring civilization.