RE: What to do about Mega Ray?
Honestly, I think Manectric decks can easily beat Ray decks. Sure, the setup might be a bit slower, but what Ray gains Manectric gains... which is Mega Turbo. You can set up a Manectric T2 capable of OHKOing the Ray either in mega or in regular form with weakness. They rely a lot on their stadium in play and 7 pokemon to consistently OHKO Manectrics...which is a lot more needed then what manectric needs, which is 2 energy and a tool attached to the opposing pokemon.
I'm just going to refer you to this video to show you how to consistently get up a T1 Ray and why it will never happen:
Emerald break = 2015 T1 Night spear; it can happen, but don't count on it.