Theory-crafting a few potential deck lists with the new 'Memory Light' tool, the first of which being Donphan EX and Lucario fixing the main problem with Fighting decks: lack of energy ramp.
In this case, each of the Pokémon has a 1-energy attack that it can use—Donphan can borrow Phanpy's 'Flail' attack and, with a 160 HP body, that means it can do upwards of 150 damage with Flail (170-190 with Lucario's 'Fighting Coach' ability); likewise, if you end up with a Turn 3 Lucario and are running behind the curve on energy, you can 'Jab' for 40 instead of waiting to 'Submarine Blow' for 60. Traveling Merchant feels like a must-have here, even only at 1, so you can actually get to your Memory Lights in short order. Other Trainers to taste—two Researches of course; I like having Sabrina and Cyrus for options; and a Pokémon Center Lady in a pinch.