On the one hand, the Single Strike VMAX alt-art is incredible
As of the time of writing, TCGPlayer didn't have enough data for an average market value on the card, but shows its most recent sale at $505.99, with a current listing at $470.99
Cards like Fan of Waves could definitely help you out as well as early game donks (if they don't get out a second basic Pokemon) There's not a lot to say about the Blacephalon matchup
Once your mana is fixed, you can cast Masked Bandits from exile, not far from warp
It could have been Prismatic Parallels or Prism Prison, among many other options
At the end of the Battle Phase of the turn this effect was used: This card is changed to Defense Position, and it cannot change it's battle position until your next turn