Be annoying to deal with and simultaneously hard to stop from questing for high amounts of lore
Planes usually have two important parts: A main ability which can be a continuous effect, such as Tazeem in Zendikar (whose ability is that creatures can't block while this plane is active), or a triggered ability, such as Undercity Reaches from Ravnica (which allows the controller to draw a card each time one of their creatures deals combat damage to a player)
Creature - Shapeshifter Color tag templates(None) Emrakul's Messenger Devoid (This card has no color.) Flying Whenever you draw your second card each turn, create a 0/1 colorless Eldrazi Spawn creature token with "Sacrifice this token: Add ." Creature - Rogue Faerie Eldrazi Color tag templates(None) Esper Sentinel Whenever an opponent casts their first noncreature spell each turn, draw a card unless that player pays , where X is this creature's power
1 Wisecrack Sorceries (3) 1 Kapow
As a 7/7 with trample, its already a nightmare to block, but the enters-the-battlefield trigger is what truly breaks the game open
Delver of Secrets is a contentious card