I think the most notable example of this is the four Sea Monster creature types that were first referenced on Quest for Ulas Temple Kraken, Leviathan, Octopus, and Serpent
Gladion's Final Battle, Special Illustration Rare (#118) and Gwynn, Special Illustration Rare (#119)
It's worth the life loss, especially in Commander, and it doesn't exile after use for recursion
As a legend turned saga creature, Clive, Ifrit's Dominant and Ifrit, Warden of Inferno is also somewhat of a ritual and removal by fighting
Quick Balls success rate is significantly better if you play a very low amount of Pokmon, and becomes comparable or even higher than Pok Balls in certain decks, but for the average Stage 2 or SP based deck, Pok Ball offers the best chance for you to get the Pokmon you need, exactly when you need it
3 mana and 3 life for 3 cards is just a great rate, and the caveat of requiring 3 colors of mana was easy to fulfill between Battle lands and fetchlands