Ruling VS Night Spin

[DNA]

I checked the Compendium first about this but I didn't find it, so I'm asking it here.

Say I have a Dusknoir that just used Night Spin last turn. My opponent then brings up a Stormfront Charizard (reprint), and it has 4 Fire energy attached. He uses Fire Spin and discards 2 of those energy.
This question can stretch across to any attacks that discard for a cost (such as Hydro Shot or Dragon Rush).

My question is: Would Fire Spin (or Hydro Shot etc.) damage Dusknoir or not?

 

[Rummage]

It would damage it because you do Damage First then check for effects. So the damage is done while Charizard has 4 energy.

 

[Mr.Ferrari]

Basically its starts with 4 and ends with 2 so yes it would hit