Pokmon card value is determined by: rarity (limited print runs), condition (PSA 10 commands premiums), historical significance (prototypes, trophy cards), iconic status (Charizard, Pikachu), grading (professionally authenticated), and market demand (collector and investor interest)
These cards might not fit in every deck, but they certainly will make an impact
In certain decks, this makes Poison one of the most effective long-term Special Conditions
First of all, your deck must contain exactly 60 cards
It does take a minus one hit on its original power, but this can still result in a very powerful card being placed under your control after its been sent to the graveyard
Getting the key cards for these decks can take timebut Pocket Swap makes it faster