Synergizing with the formats slower pace and multiplayer nature, Esper Sentinel can often draw you multiple cards per turn
Bumbleflower down on turn three with a mana or two to spare to immediately begin handing out counters and cards

Aang and La, Ocean's Fury Abaddon the Despoiler Aberrant Aberrant Manawurm Abominable Treefolk Abomination, Irradiated Brute Abomination, Terrifying Titan Abomination, World Ravager Abyssal Persecutor Advent of the Wurm Aetherstream Leopard Aetherwind Basker Agatha of the Vile Cauldron Agatha's Champion Agent Frank Horrigan Aggression Aggressive Mammoth Agonasaur Rex Ajani's Comrade Ajani, Valiant Protector Akawalli, the Seething Tower Akoum Stonewaker Akoum Warrior Akroma's Memorial Akroma, Angel of Fury Akroma, Angel of Wrath Akroma, Angel of Wrath Avatar Akroma, Vision of Ixidor Aku Djinn Akul the Unrepentant Alexios, Deimos of Kosmos Almighty Brushwagg Aloe Alchemist Alpha Deathclaw Altanak, the Thrice-Called Altar Golem Altar of the Goyf Amarant Coral Ambush Krotiq Anax and Cymede Ancestral Anger Ancient Imperiosaur Ancient Stone Idol Ancient of the Equinox Anep, Vizier of Hazoret Angelfire Ignition Angry Mob Angry Rabble Annoyed Altisaur Ant-Man, Reformed Rogue Appeal // Authority Appeal // Authority Arahbo, Roar of the World Arbalest Engineers Arborback Stomper Arcane Archery Arcbound Crusher Archdemon of Greed Archdemon of Unx Archetype of Aggression Archon of Valor's Reach Archweaver Arctic Nishoba Argothian Swine Argothian Wurm Arlinn, Embraced by the Moon Arlinn, the Moon's Fury Armada Wurm Armadillo Cloak Armory Paladin Arrogant Wurm Ashroot Animist

Characters with Challenger are most effective at removing opponents characters from play, rather than questing to earn Lore on their own
Then the instants that sacrifice a dork to draw two cards are next, like the first one in Village Rites or many others
A 5-mana two-card tutor outside of black is a fair rate, especially in singleton formats like Commander