High Class Packs (HCPs) are premium Japanese sets with boosted pull rates and curated card pools drawn from multiple standard expansions
For roughly $2, its one of the best and most reliable counterspells you can play
The Land Before Battlefields Adrian Sullivan recently wrote a great study on the merits and history of the Prison strategy
Cool Combos: Situation A: Consider the following combination of cards (WITH NO OTHER SETUP): Molten Conduction Field , Reinforcement of the Army/Laval Cannon , and Laval Coatl / Laval Burner: Use Molten, sending and Laval Lakeside Lady to the Graveyard Laval Volcano Handmaiden Maiden activates, sending another, which sends another, who then sends to the Graveyard Laval Forest Sprite Special Summon your Coatl or Burner (or multiple if you have them in hand) Banish Lakeside and Forest Sprite from your Graveyard, then destroy a set card your opponent controls
As it stands, it feels like a rare from a Modern Horizons set that was mysteriously printed into Standard