Some were short-lived, and some have survived for quite a long time
#1 - Teval, the Balanced ScaleTeval, the Balanced Scale For several years, I've been tuning a Kamahl, Heart of KrosaKamahl, Heart of Krosa // Tormod, the DesecratorTormod, the Desecrator deck
Ow, they answer, to avoid taking further damage from Ow
However, in competitive Magic: The Gathering play, there are likely better options available, such as more efficient creatures with similar abilities like Stuffy Doll or Boros Reckoner, which offer additional utility or resilience
You must run this in Madness, Discard Brews or Graveyard and Reanimation too, just toss in Monument of Endurance to draw from it outside of them since you can cast what you discard with madness
Currently, its unclear what this will do to their price in the long run