If you want Ray and Resh, with Zebstrika(evolvable on T1 from Blitzle via Wally) being the Colorless M-Ray deck's incoming death nail(being released in BREAKPoint), with:
MRay Colorless weak to Lightning + a Fighting Resistance + 220 HP + Zebstrika's Ability that bypasses Altaria's ability that would've negated weakness had said ability was absent(Zebstrika's ability negates effects on opposing Actives, so Altaria's ability becomes moot against Zebstrika)...
^ how about a deck that uses the other Mega, and Golduck BREAK, to go along w/ Resh, or better yet, if going the MRay Dragon route, Resh can be dropped for Team Magma's Camerupt + Blacksmith + Max Potion:
-1 Reshiram(if going the Resh route)
-4 Reshiram(if going the Magma Camerupt route)
-3 M Rayquaza-EX Colorless(if you want the Dragon version...)
-1 Shaymin-EX(if KO damage is not based on bench, the third shaymin is unnecessary)
-1 Swablu(if both rayquaza forms used are not colorless, no need for Altaria's ability...)
-1 Altaria(if both rayquaza forms used are not colorless, no need for Altaria's ability...)
-1 Hoopa-EX(To make room for Golduck BREAK, unfortunately, cut the fat in order to ensure the pokemon count does not reach 20 and take up too much room to allow for vital Trainers in a 60-card deck...)
+2 Magma's Numel(if going the Magma Camerupt route)
+2 Magma's Camerupt(if going the Magma Camerupt route)
+3 M Rayquaza-EX Dragon(if you want the Dragon version...)
+2 Psyduck(for Golduck BREAK)
+2 Golduck(for Golduck BREAK)
+2 Golduck BREAK(Hyper Trans)
-4 Acro Bike(scorched earth makes this card unnecessary: both cards on top two kept and put in hand vs. one card on top two kept and put in hand with the other discarded)
-4 Skyfield(No bench requirement for damage? If true, then this stadium is unnecessary)
-1 VS Seeker(The changes make a two pokemon overage if the total Trainer count is not altered, but 3 VS Seekers is not a bad count...)
-1 Switch(Item card one-of? Not a good way to use a one-of, especially since there's a chance that it could be Prized to deny you immediate access to that card, and what if it's the difference between your survival and losing a game? Since this deck's tight on space, ditch this: there's no room for this AND Golduck BREAK, so choose one or the other...)
+3 Scorched Earth(For better opening draw)
+1 Wally(For the chance of getting Golduck to BREAK on T2 over T3)
+2 Blacksmith(To ensure that at least 3 fire energy is gained by TM Camerupt in the course of one turn, in which case you can transfer them w/ Goludck BREAK's Hyper Trans)
+2 Max Potion(if your pokemon has nearly enough damage counters to be on the brink of getting KO'd, and yet you have a way to get all energy off of it to ensure no negative side effects like all energy removed after it is fully healed by means of Max Potion, why not use the aforementioned item?)
-4 DCE(Golduck BREAK decks don't run well w/ Special energy: they can't be transferred w/ Hyper Trans)
+1 Fire Energy
+3 Lightning Energy(for MRay Dragon's attack for 300 damage: since the max HP a pokemon normally starts out with is 250 so far...)
^ Phew. A lot of typing...
^ Like my idea? I know it's a major change, but as I doubt that MRay Colorless(unless you think I'm overestimating Zebstrika from Breakpoint, in which case, I understand) can last past BREAKPoint's release, especially w/ DCE-and-KO Zebstrika, my idea could be a way around that... But what do you think?