[SPOILER] Plot Discussion Thread *Spoiler Alert*

[Lazoriss]

I originally thought the orange glow was from the lantern, but he appears to be holding it in his other arm...

Not if it's a reflection

Yes, the glow being lantern light would match its position in-game, seeing how it's mirrored and the lantern is wielded by your left hand. But I wouldn't expect the artist to be THAT acute in detail. The orange glow is most likely there for aesthetic reasons (orange compliments blue and yadayada).