Warp and Void Warp lets you play it from your hand for warp cost, exile beginning of next end step, then cast it from exile on a later turn
This card also allows its user to accrue value over time, as whenever Esika's Chariot attacks, its controller creates a copy of any token they control
Its popularity in Commander, however, is what buoys the card's price tag
In essence: a game plan and interaction for what your opponents could play is often more important than the cards you want to play or open with
Diminishing Returns Its been many years since people ran Diminishing Returns in any real tournament format, but you didnt think I was going to leave Forgetful Fish off the list, did you
It taps for colorless mana, but you can sacrifice it to destroy a land, an ability that becomes truly oppressive when you pair it with Crucible of Worlds or Icetill Explorer