Herald's Horn and Shadow in the Warp also shave some mana off your expensive creatures while providing other benefits
Iconic Cards: Tarmogoyf, Dark Confidant, Lightning Bolt, Birds of Paradise, Liliana of the Veil Popular Decks: Abzan Junk, The Rock, Jund, Superfriends 4 Tempo Tempo decks aim to stay one step ahead of their opponents by ruining the opponents plan
They also give it the stats to become a great blocker to stop your opponents from getting too aggressive while you chip away at their life total
Instead of playing as the main character, you will be the bad guy of the story
You might never actually use Wrenn and Seven's ultimate ability, but if you're playing a deck that just focuses on the land-filtering part of this planeswalker, it's nice to know you can still get back those discarded permanents later
Instead, this extra layer of versatility allows Boommobile to be a mana sink once you can cast it