The Scenario
Greater Sci-Fi combatant
Hmmm, timeline. Yes, it'd be great if Skyward Sword tied all of this together, but I'm skeptical given how Legend of Zelda usually seems to be about things like this. It's not going to be obvious, that's for sure.
However, now that you mention it, Ghirihim's powers are extremely reminiscent of twilight based effects, what with the particles and stuff. He also mentions a servant of the goddesses, so Light Spirit or something. I doubt Link is wielding the Picori Blade however, if only because the story is focused on the origin of the Master Sword from the Skyward Sword. Unless the Skyward Sword is split or something, one part becoming the Picori Blade (later Four Sword) and the other becoming the Master Sword.
Now, correct me if I'm wrong since I'm not too good at timeline stuff, but Minish Cap is the earliest in the timeline, followed by Ocarina of Time, then Twilight Princess and then Link to the Past? Of those named, at least. Skyward Sword is now going to be the earliest, then, with the origin of Hyrule and the Master Sword, possibly the Picori Blade and Light Force.