Mine's probably Trifurcated Strike. It's just incredibly strong once you get even one attack up on the creature, essentially creating a game-winning card all on its own. 1 health is also usually irrelevant if you place the creature well or if you just kill the opponent fast enough.
I also ended up liking the keyword that moves your creature at the end of the round - forgot what its called. In combination with Trifurcated or Bifurcated Strike, you can make for some good board presence via the creature's mobility whilst also making it a little more evasive.
What's yours?
Side note: the only post on here is from two years ago and there hasn't been any other activity. Maybe we can revive this community? Lemmy seems to be in a much healthier and active spot compared to two years ago - I could imagine some activity here :)
Maybe there's also not as much to discuss compared to a very political and philosophical game like Disco Elysium, even though gameplay is non-existent there. It's true, though, that it doesn't take too much to get things going on Lemmy nowadays. I remember starting to populate /c/Soulslike. It also took some time to get a relatively active community going, but it worked out in the end.