Well, with the Welder in the same set, which is a better Blacksmith since the attachment can be on any pokemon type, without type-related restrictions like those that the Blacksmith lays down on its card text, the Expanded format could see the Colorless Mega Ray(CMR) be overtaken in terms of card usage percentage by the once-inferior Dragon Mega Ray(DMR), but Mega Ray still will have a bad counter, regardless of its type. No matter, just one use of new Volcanion's first attack going second to power up your desired DMR on turn 1, then use Welder once on turn 2 going second combined a Lightning attachment for turn, since DMR needs 3 Fire, 1 Lightning, and 1 Colorless to attack w/ Dragon Ascent, but if you can't get Volc out or don't have the Energy in your hand to even be able to use its attack on T1 going second, or even if you're going first on T1, don't worry: Either one fire energy attachment for turn(best done on turn 1) AND two Welders(unless you use Lt. Surge prior to the Welders, since Welder is a Supporter, two of such cannot be used on same turn, don't be fooled) OR 1 Kiawe on T1, and then, all you have to worry about is the 1 Lightning attachment it needs afterward to use Dragon Ascent for 300. And after that, don't forget to use Welder again next turn to deal with the effect-induced discard, and watch decks get crushed... Yeah... I wish it was THAT easy to tell deck greatness on paper, but in reality, life isn't like that...
^ As for CMR, it has seen better days in Expanded, crippled by bench reducer cards like Parallel City and Sudowoodo GRI, not to mention that, come Unbroken Bonds, Honchkrow-GX might have a heyday shutting down Mega Evolution decks, so both possible MegaRays could be inferior anyway due to the rise of the Dark types... Or will they???
We'll see after some playtesting...