You can give all your artifact creatures and vehicles a +1/+1 counter each turn, and then turn those counters into card draw after combat
I feel like they came out of nowhere post- Kaldheim and became a force to be reckoned with in just a year or two
When paired with edict effects that can force each player to sacrifice a creature, Vren is going to create an unstoppable board very quickly, and that's ignoring all the death triggers that will occur as players attack and block each other's creatures
Headliner card in less than 1% of boosters
I might flip through more binders and take a quick peek at the bulk for the sake of the seller, but once I know I'm buying the collection, the counting stops
It's a pretty simple concept that opens up a lot of different lines of play once you start to get the hang of the basics of the game, but at the same time, none of these cards are so overly complex that they're too daunting for beginners like myself