Somehow, I feel like Merton is the key to this riddle, and I can't think of a Merton in FF7, but it seems familiar to me :I

Now, when you say it's not Da-Chao, do you mean that it has nothing to do with Da-Chao?

My guess is climbing up the wire to go to the headquarters.

High as you can go
It's pretty high up, yo

An expansive vista
That you cannot see
The way the camera is pointed, you can't see behind you, which would show a large expanse of land, or the town, or whatever.

Mertons behind you
Umm, there is someone named Merton in the Wall Market? XD