Who is the voice who tells you how to lift the fog (Pokemon Mystery Dungeon explorers of TDS)

[Jirachii.]

Hey,

I recently started playing Pokemon Mystery Dungeon Explorers of (the?) Sky, and I love it just as much as I did before. However one thing I don't quite understand. For most part, the Dimensional Scream is pretty obvious. However, when you go through Foggy Forest, you arrive at a Groudon statue. You touch it, activate the Dimensional Scream and a voice tells how to lift the fog.

I am wondering, who is the voice? I doubt it's Grovyle as the time gear at that point isn't stolen. Neither can it be you in the past as you came from the future and I would assume the place wouldn't be the same (regardless, I would say you would recognize your own voice).

What or who do you think - or is it confirmed somewhere - the voice that tells you the next lines is?

That's it! It's here! It's here!
I see. Place the Drought Stone into Groudon's heart. That lifts the fog! Very well done! Good job, partner!

 

[Palamon]

If you don't care about it being spoiled, it really is Grovyle's voice. You, the player, just don't remember because amnesia and whatnot. I won't say when the reveal takes place that it is Grovyle. Just continue playing the game, and you'll see.

 

[Jirachii.]

If you don't care about it being spoiled, it really is Grovyle's voice. You, the player, just don't remember because amnesia and whatnot. I won't say when the reveal takes place that it is Grovyle. Just continue playing the game, and you'll see.

I've played the game before. I'm just confused about this part. I know that Grovyle couldn't have been there with you because then Uxie would've remembered you. But in case it's after the amnesia, then how come the time gear wasn't stolen yet for several days later? If Grovyle was ahead of you and the guild, wouldn't it mean he would've been at the lake much sooner? Or am I just missing some detail?