For example, you can't exile more than six cards from your graveyard to cast Sorcerous Squall unless an effect has increased its cost
If you happen to be building a strict theme deck, you will probably want to dip into almost all of these cards, as well as Might of Oaks (the Urza's Legacy, version), Monstrous Growth (the Portal Second Age, version), and the amazing Squirrel cards before Odyssey
Many names of spells, effects, and items come straight out of a Dungeons Masters Guide or Players Handbook: Lightning Bolt Crystal Ball Fireball Phantasmal Forces Clone Invisibility Fabricate Ball Lightning Erase Fear Misdirection Jump Simulacrum Sleep Web Sunstone Shatter Visions Wall of Fire Wall of Stone Wall of Ice Wall of Sand Wall of Bone Pyrotechnics Ice Storm Reincarnate Descent into Madness Dehydration Brand Chain Lightning Entomb Dominate Animate Dead Teleport Resurrection Raise Dead And then you have similar effects like Phantasmal Terrain instead of Hallucinatory Terrain or Phantasmal Mount vs Phantom Steed, Fly vs Flight, etc
Tapping down an Urzas Tower in your opponents upkeep can effectively Time Walk them, and it can give a number of decks that little bit of time they need to take over
It's because local shops, pawn shops or tournaments are only interested in rare cards
Newest versions of the deck fit in multiple subtle ways to cash in on any surplus mana generation: Natures Rhythm is as good for combo as youd expect of a tutor you can cast twice, and Repulsive Mutation is templated beautifully to allow maximum usage in any scenario, defensive or offensive Mockingbird is an amazing choice for increasing the effective density of your signature creatures, all of which stack in multiples