Poison Counters You know em, you hate/love em
Whether youre looking to break into Modern or Legacy with a competitive deck or want to sit down with your friends for some Commander fun, Elves are a great deck to pick up and play
You want to be able to cast a spell or two every turn, and having too many expensive cards will stop you doing that
Taking a spell and removing it from relevance for a few turns is a perfect encapsulation of tempo, in that youre not actually dealing with the card outright, and are instead just delaying the inevitable
Rotting Regisaur has been popping up in a lot of Cubes largely for the discard outlet coupled with a meaty threat in and of itself for Reanimator strategies, and because its a card that plays reasonably in beatdown decks as well
Im not sure about Knights, but Merfolk getting a pile of +1/+1 counters is downright dangerous