My personal favorite would have to be the Lost Zone buff
Since were in Izzet colors, I can play classic counterspells and burn spells to control the board as needed
Not many non-combo decks can support card quality, even card quality with synergy, when it comes at a card advantage cost
Some collectors organize by set, some by Pokmon, some by whats worth money
(im leaving the descriptions written just in case, but you can read the directly from the card below.) (And you can see my older Vehicroid Support pages if you want) 1-Carrierroid: When an opponent activates a card's effect that targets a "roid" monster you control, you can discard 1 card to negate its activation and destroy the card
However, it became apparent that people loved Historic a lot as its own thing so Wizards went all-in on prioritizing that over Pioneer, where it would likely take years to add all the cards to the client