Do you feel this new core is extremely powerful? It removes all of your defenses for 3 turns AND does not allow you to use your cores. Now for 3 turns, that is a VERY powerful effect. But then again, it may just me being a whiner, so do you feel this new core is OP and needs balance? If so, how would you balance it?
I have no reason to criticize the core yet, but I am not pleased with the environment in which another core like this was added to (attack spam, rage grinding, glass cannons).
It is pretty balanced, because it is merely removing the resistances and defenses invested in an armor for two turns. An easy counter for this move would be Energy Shield and Matrix for points that are shifted mainly to Defense or Resistance. If it's split between two, have fun with that.