Using "Flash"

[Dr Blazikovzki]

I came across a problem, which considers using flash in the "Dark Cave" just before city 2. Could anyone help me to figure out how to light up this cave? I can't seem to do this.

PS. I did learn the skill to a pokemon, it even has it as attack, though I can't seem to use it.

~ Dr Blazikovzki

 

[Darkfire]

Flash doesn't work in the over world yet
also you may notice that it is a damaging electric attack
this is on purpose

 

[Dr Blazikovzki]

ohh oke, yeah found it strange it was. Good thing is does have a use though.
Thanks for helping.