Curious as to what this piece of music is based off of

[Yash]

I'm pretty sure it's a remix of one of the battle songs from the games, and it's used pretty frequently (it gets kept occasionally in the dub).

http://youtube.com/watch?v=4gN4UqZFxiI

It starts at 4:44 in this clip.

 

[PDL]

It's the final battle music when you face your rivial in RBY.