For four mana, you get to essentially draw another card each turn while sometimes making a token

Scientists Aang's Defense Abandon Attachments Aberrant Abeyance Abomination of Gudul Abundance Abundant Growth Abzan Banner Abzan Beastmaster Academic Dispute Academy Elite Academy Raider Academy Wall Accelerate Accumulated Knowledge Aclazotz, Deepest Betrayal Acquisition Octopus Acrobatic Maneuver Action News Crew Adrestia Advancing the Spirit Adventure Awaits Adventurer's Airship Aegar, the Freezing Flame Aeon Chronicler Aerial Extortionist Aesi, Tyrant of Gyre Strait Aether Channeler Aether Spellbomb Aether Syphon Afflict Afterlife Insurance Agency Coroner Agent 13, Sharon Carter Agent Maria Hill Agent Venom Agent's Toolkit Aggressive Urge Agna Qel'a Agonasaur Rex Ahriman Air Nomad Legacy Airbending Lesson Airborne Aid Airship Crash Airship Engine Room Akiri, Fearless Voyager Akki Ronin Akki Scrapchomper Akoum Flameseeker Akroma's Blessing Akroma's Vengeance Aladdin's Lamp Alandra, Sky Dreamer Alania, Divergent Storm Alaundo the Seer Alchemist's Apprentice Alchemist's Vial Aleatory Alhammarret's Archive All-Seeing Arbiter Alms Collector Alphinaud Leveilleur Alquist Proft, Master Sleuth Altanak, the Thrice-Called Altar of the Wretched Amass the Components Amber Gristle O'Maul Ambitious Assault Aminatou, Veil Piercer

If the metagame holds true (which it may notI am writing this several weeks in advance), I'd expect to see some of these tactics on display at the Pro Tour this weekend
Each survival ability is a triggered ability that triggers at the beginning of your second main phase, if the creature with the ability is tapped
Cards like Cloud, Midgar Mercenary and Vivi Ornitier (extended)which had prices in the hundreds or even thousands of dollars last week due to low supply during presalesare now down to a more reasonable $37 and $90, respectively