This is called fizzling in game slang
While a strong card in general, Wrenn and Six is especially powerful in Legacy because of its interaction with Wasteland and the historic prevalence of metagame-defining 1-toughness creatures like Mother of Runes
Mana Crypt, Dockside Extortionist, and Jewelled Lotus are staying banned
For now, I'll cross my fingers and hope for a desirable outcome
Ruby lets you banish threats before they spiral out of control, while Steel ensures you have staying power through late-game defenses

Krenko Goblins Krenko, Mob Boss | Illustration by Karl Kopinski Commander (1) Creature (26) Goblin Chirurgeon Goblin Lackey Skirk Prospector Marvin, Murderous Mimic Battle Cry Goblin Goblin Instigator Goblin Recruiter Hexing Squelcher Rundvelt Hordemaster Scuzzback Scrounger Warren Torchmaster Conspicuous Snoop Warren Instigator General Kreat, the Boltbringer Goblin Matron Goblin Sharpshooter Howlsquad Heavy Krenko, Tin Street Kingpin Molten Gatekeeper Pashalik Mons Goblin Chieftain Goblin King Goblin Warchief Hobgoblin Bandit Lord Purphoros, God of the Forge Goblin Trashmaster Sorcery (8) Gamble Goblin War Strike Shattering Spree Dragon Fodder Krenko's Command Jeska's Will Hordeling Outburst Will of the Jeskai Instant (9) Brightstone Ritual Lightning Bolt Pyroblast Redirect Lightning Battle Hymn Untimely Malfunction Chaos Warp Reiterate Zuko's Exile Enchantment (4) Goblin Bombardment Impact Tremors Shared Animosity City on Fire Artifact (16) Commander's Plate Skullclamp Sol Ring Arcane Signet Lightning Greaves Swiftfoot Boots Thornbite Staff Throne of the God-Pharaoh Ashnod's Altar Patriar's Seal Staff of Domination Thousand-Year Elixir Helm of the Host Banner of Kinship Coat of Arms Eldrazi Monument Land (36) Ancient Tomb Arena of Glory Cavern of Souls Hall of the Bandit Lord Mines of Moria Three Tree City Mountain x30 This cEDH Krenko, Mob Boss list wants to explode out of the gate, stick Krenko, and start to multiply goblins before the table can stabilize
