Armarouge EX's attack deals 40+40*(Fire Energy) damage (which is absolutely ridiculous by the way), atatch as many fire energies as possible onto Armarouge as possible using any combination of Welder. Emboar and Coalossal and have Charizard double the energy, you can easily get at least 3 energy attatchments per turn, and if you have five energies attatched to Armarouge (extremely easy to achieve) it'll deal 40+40*5*2 = 440 damage.
Some fun things include Radiant Greninja being a free attatchment with Coalossal while also being 2 free cards and drawing lady with Emboar out being a +4 energy onto Armarouge