Energy Protection

[typhlosion collector]

one of my friends and i were battling, i evolved my Larvitar SF into a Pupitar SF, and i had 4 energies attached to my pupitar when i evolved. But my friend said that i could only reduce 30 damage when the card said that for every energy attached to pupitar SF is reduced by 10 damage but not by 30 in this way, but i think that i can reduce more than 30 damage for each energy i attach to my pupitar. So who is right, me or my friend?

 

[PokePop]

The card clearly says "you can't reduce more than 30 damage in this way" so I'm not sure what is confusing.
You can only reduce 30 damage. Total. 10 for each energy. Only up to 3 of them.
Of course, this applies to each attack that tries to damage you. It's not a one time effect.