Eriette Voltron | Commander | Abe Sargent Commander (1) 1 Eriette of the Charmed Apple Creatures (12) 1 Archon of Sun's Grace 1 Ardenn, Intrepid Archeologist 1 Ashiok's Reaper 1 Doomwake Giant 1 Eidolon of Countless Battles 1 Hateful Eidolon 1 Kor Spiritdancer 1 Mesa Enchantress 1 Ondu Spiritdancer 1 Solemn Simulacrum 1 Sram, Senior Edificer 1 Windborn Muse Instants (4) 1 Generous Gift 1 Surge of Salvation 1 Teferi's Protection 1 Utter End Sorceries (8) 1 Austere Command 1 Brilliant Restoration 1 Idyllic Tutor 1 Open the Vaults 1 Retether 1 Promise of Loyalty 1 Three Dreams 1 Vindicate Enchantments (27) 1 All that Glitters 1 Angelic Destiny 1 Clawing Torment 1 Darksteel Mutation 1 Demonic Embrace 1 Ethereal Armor 1 Ghostly Prison 1 Ghoulish Impetus 1 Grisly Transformation 1 Gryff's Boon 1 Land Tax 1 Liliana's Contract 1 Martial Impetus 1 Parasitic Impetus 1 Phyrexian Arena 1 Sage's Reverie 1 Sigil of the Empty Throne 1 Smothering Tithe 1 Sphere of Safety 1 Spirit Loop 1 Spirit Mantle 1 Tenuous Truce 1 Underworld Connections 1 Unholy Indenture 1 Unquestioned Authority 1 Vow of Malice 1 Vow of Torment Artifacts (10) 1 Arcane Signet 1 Bloodthirsty Blade 1 Commander's Sphere 1 Decanter of Endless Water 1 Orzhov Signet 1 Sol Ring 1 Stonespeaker Crystal 1 Swiftfoot Boots 1 Thought Vessel 1 Well of Lost Dreams Lands (37) 8 Plains 8 Swamp1 Access Tunnel 1 Arcane Lighthouse 1 Bojuka Bog 1 Caves of Koilos 1 Command Tower 1 Detection Tower 1 Eiganjo, Seat of the Empire 1 Godless Shrine 1 Hall of Heliod's Generosity 1 Isolated Chapel 1 Kor Haven 1 Labyrinth of Skophos 1 Maze of Ith 1 Orzhov Basilica 1 Rogue's Passage 1 Serra's Sanctum 1 Shizo, Death's Storehouse 1 Snowfield Sinkhole 1 Sunlight Marsh 1 Temple of Silence 1 Vault of Champions 1 War Room And there we go

Creatures with much higher mana values can suddenly spring up on your battlefield when you have nowhere near enough mana to normally cast it
Legality depends on the tournament format -- Mystic Retrieval can be legal in some formats and banned or restricted in others
A firebreathing goat steedwith obligatory mountainwalkmakes approximately zero sense
It's known for his intelligence, cunning, and mastery of mental magic
If that land is a Plains, you may return that nonland permanent card to the battlefield instead