If you make it drain energy then shield pack cappers would never be able to make it out of the base if they took enough damage to drain their whole energy pool.
Then what good is it to use the shield pack for capping when you'r losing energy (bread and butter of flying) or even dueling?
TL:TR...
I never said anything about making the Shield Core like the tribes Shield pack.
I proposed a different design approach, why does it need to use energy at all is the point I'm getting at...
BUY THE NEW RAZER BLADE. SO WORTH IT, TO WRITE IN CAPS.
Uber do some games use 6 cores?
Well if you split it up 4 cores can be used to run a game while you have 2 spare that run the misc. programs in the BG. Just thoughts.