I think they got to echo because the "pay a fee to keep the card" aspect felt similar to echo
C Common Guardian Ceal X FIRE Level 4 [ PyroEffect ] ATK 1700 DEF 1400 Cannot be Summoned unless you control a face-up "Shooting Star Bow - Ceal"
The adventure part of Bramble Familiar, Fetch Quest, has you milling seven cards to return an enchantment, creature, or land from among those cards directly into play
Not only was the fledgling format exclusive to MTG Arena, but it leveraged that digital platform, arguably for the worse
Here is my favorite Town design that didn't work out as it added yet another source of tracking complexity: Besaid, Place You Can Visit Land Town CARDNAME enters the battlefield tapped
The Beast, Deathless Prince One of the things Ive always liked about Rakdos is that they get a lot of designs that put emphasis on very specific or unconventional mechanics