bloomburrow set booster box Amazon.com: Magic: The Gathering Play stamped Signature Art card can be found in 5% of packs.) Each pack includes a combination of 1–4 cards of rarity Rare or higher and 3–5 Uncommon MTG: Bloomburrow - Play Booster

On top of that, there are secret cards numbered above 204 with a special Enchanted rarity

Tenpai Dragon Genroku X FIRE Level 3 [ Dragon / Effect ] ATK 0 DEF 1000 If this card is added to your hand, except by drawing it: You can Special Summon this card as a Tuner, then you can increase its Level by 1

Creature card from the Magic The Gathering set Adventures in the Forgotten Realms - Commander (MTG-AFC-326)

Because of how difficult the mechanic is to balance and how it's tied to the Phyrexians, it's unlikely well ever see the keyword outside of sets themed around Phyrexia

Especially when I have opponents asking me questions like how much damage etc