1) Heartbeat of Spring ( Champions of Kamigawa ) During the development of Fifth Edition (back in something like 1997), the team made of wish list of cards it wanted to see in future base sets
Whenever another creature you control with power 4 or greater enters, draw a card
Collectors will also have plenty to chase
In black border, we can make cards that care about a game state (how many creatures you control, how many cards are in your graveyard, how many cards are in your hand, etc.) that will vary as the game progresses
Cycling is a keyword that works pretty well with that plan, as discarding will help to build up the graveyard
Similarly, the difference in black borders on a real card (left) and a fake (right) are pretty striking when looking at the green dot on the card back, but that's just one thing we're interested in