If you were a hungry child with a sweet tooth, you might be sitting on a pile of gold, like the Meowth in this art
Goose into Oko into Questing Beast...yikes
Goblin Electromancers effect reduces that cost by , so when you actually pay the mana to cast Banefire, you only end up paying , even though X equals 5

3 Blood Cultist Boltbender Boris Devilboon Boros Guildmage Boros Reckoner Burning Prophet Burning-Fist Minotaur Cadric, Soul Kindler Celes, Rune Knight Cinder Seer Coruscation Mage Crackling Cyclops Crackling Spellslinger Cyclops Electromancer Cyclops Superconductor Dismissive Pyromancer Dragon Mage Drannith Stinger Dreadhorde Arcanist Dualcaster Mage Dwarven Forge-Chanter Dynaheir, Invoker Adept Ecstatic Electromancer Electrostatic Infantry Elemental Expressionist Embermage Goblin Embodiment of Flame Emeritus of Conflict Eruth, Tormented Prophet Esper Terra Etherium-Horn Sorcerer Exhibition Magician Fervent Paincaster Firefist Adept Fireslinger Fissure Wizard Flame Channeler Flamekin Herald Gandalf of the Secret Fire Gandalf the Grey Garth One-Eye Ghen, Arcanum Weaver Ghitu Amplifier Ghitu Chronicler Ghitu Journeymage Ghitu Lavarunner Gleeful Arsonist Goblin Cruciverbalist Goblin Electromancer Goblin Flectomancer Goblin Pyromancer Goblin Researcher Goblin Test Pilot Goblin Wizard Gogo, Mysterious Mime Goliath Daydreamer Grim Lavamancer

The latter category is our subject today, and there are broken things to do when you allow cards to break the rules of timing