Sagas love to be bounced/blinked so you can re-use their effects, so it's great in a deck with Vedalken Mastermind or Brago, King Eternal
Holons Castform was also essential in Delta Species decks like Metanite (Metagross /Dragonite ) and Raieggs (Raichu /Exeggutor ), as it gave unparalleled draw power in the early stages of the game
Note that they arent unique in terms of rules
When Ravnica was released the very next year, I immediately made a note to include Zephyr Spirit in my list of worst creatures of all time
The idea of naming a card in an opponents hand and then getting to keep or discard those cards you correctly guessed goes back to childhood games like Old Maid
While players were only allowed to include one Radiant Pokmon in their decks, this card was often a crucial tech choice that enabled some decks' most important combos , and they will be sorely missed