Clefable

[Black Mamba]

If I use a boost energy on Clefable DP to use metronome against an Electivire DP, can I do 120 damage with intense voltage by discarding all Lighting energies, even if there are 0? I understand I can use Infernape's Flare Blitz attack, but can I do the same thing if it is an option instead of a requirement?

 

[PokePop]

No, you have to discard at least one L to get the bonus damage.

As for Flare Blitz, actually you would have to discard at least one Fire to be able to do that as well!