Reshiram & Charizard GX's Attack can Knock Out almost any Pokemon with 1 Hit even Tag Team GX Pokemon. But, its Attack Require quite a number of Fire Energy.
Fire Strike Attack does 230 Damage and it require 4 Energy Cards to use it. Also, you can't use that Attack during your next Attack.
The other Attack Double Blaze GX Attack has 200 Base Damage for 3 Fire Energy and the Damage can be increased up to 300 if you have total of 6 Fire Energy Cards attached to Reshiram & Charizard GX.
Full Article at https://ptcg92.blogspot.com/2019/09/reshiram-charizard-gx-unbroken-bond.html
