...
right.
Here is a tree, here are other trees way off. Let's see if you can see the other ones.
"We're not gonna talk about that right now (Trophy Kills), but it's something you should do a lot of, because you're gonna need it"
"And doing this (siphoning) will charge the energy for your weapons, but not your cloak"
At the GTTV preshow, you can clearly see him stab himself with the medisticks. His energy bar doesn't move.
So trophies may be for either or both, but it rather clearly isn't for his charge.