In the best deck, Articuno ex is used as a backup big hitter in case you can't set Palkia up quickly, but some versions of this deck go with Starmie ex instead
In Volcanion and the Mechanical Marvel , a Banette that can Mega Evolve was under the control of Levi and Cherie's Mega Wave
Book Devourer Borrowed Knowledge Brand Break Asunder Breakthrough Byway Barterer Canyon Crab Careful Study Carnage Interpreter Case of the Crimson Pulse Catalog Cephalid Sage Ceta Sanctuary Chains of Mephistopheles Chakra Meditation Chandra, Flame's Catalyst Chandra, Flamecaller Change of Fortune Choking Tethers Claws of Wirewood Clear Clive, Ifrit's Dominant Cloud of Faeries Complicate Compulsion Conqueror's Foothold Contract from Below Control of the Court Cool but Rude Coralhelm Chronicler Cram Session Customs Depot Dangerous Wager Darkwatch Elves Death Pulse Decaying Time Loop Dirge of Dread Disciple of Grace Disciple of Law Disciple of Malice Divide by Zero
The same rules about what information may be written on substitute cards apply
We are likely to see the emergence of a much healthier rock-paper-scissors metagame, with midrange, control, and a new form of aggro keeping each other in check