Dialga with Adaman

This take on Dialga uses the Bird Keeper engine to maximize your usage of Mew and offer switch out when you start a V pokemon. Notable includes are 2 VIP pass, air balloon, Celebrations Dialga, Raihan, Pyukumuku and Adaman. In my testing Adaman can win games but it might be too situational and in nearly every case where it could be used, Raihan is better. Cyllene or Avery might be suitable replacements, or you could cut altogether and replace with something like Big Charm for extra protection. Air

This take on Dialga uses the Bird Keeper engine to maximize your usage of Mew and offer switch out when you start a V pokemon. Notable includes are 2 VIP pass, air balloon, Celebrations Dialga, Raihan, Pyukumuku and Adaman. In my testing Adaman can win games but it might be too situational and in nearly every case where it could be used, Raihan is better. Cyllene or Avery might be suitable replacements, or you could cut altogether and replace with something like Big Charm for extra protection. Air Balloon is very good, Pyukumuku is fine (good way to use ball search cards late game), VIP pass is probably worth at least one copy, and Celebrations Dialga is a great counter to Miltank. CEL Dialga allows you to win the Blissey and Mewtwo VUnion matchup, without it you just lose. Additionally, using Temporal Backflow can give access to Metal Saucer which can help set up a second Dialga or Zacian V after the first one goes down. An alternative play is Cancelling Cologne, but CEL Dialga is just better and is a good 3rd attacker in any matchup if it comes down to it. I dislike Hisuian Heavy ball because it rarely gets something you need, but when you prize a Dialga, Greninja or Pyukumuku it can be clutch. I find that your hands often get so big that it can be hard to use Crobat after the second turn but that's generally not a problem, and it offers a safety net if you get Marnie'd into a bad hand.