The thing with using skyfield as your stadium vs a mega ray player is that when they use hex maniac, they will more than likely to ohko giratina rather than 2hko with a different stadium.
I have a similar list to this, but instead of Skyfield, I use Faded Town since it makes winning against Mega Ray decks that much easier.
I also use AT Bunnelby to recycle DDE & Solrock (Primal Clash) to get DDE into my hand.