I cannot see these two being run together,
I don't see any reason to put special energy in a rayquaza deck.
You run eelektrik to power up lightning, and you run a couple of BASIC fire energy to sit on rayquaza to pay for the cost.
Using blend just opens you up to crash/remodelling/whateveritscalled hammer with no actual benefit aside from making you weaker against drifblim, and not being able to recover it if it goes to the discard.
the only use i can currently see for running blend energy would be to power a shaymin ex in the deck late game, however for 3 lightning energy Rayzuaza will be able to OHKO EVERYTHING in the format (bar wailord which won't be run, and some EXs with eviolite) so there is no point in shaymin ex as its a weaker, squishier attacker that runs off different energy to the rest of your deck.
At least this is my take on it