For example, if you have a three-drop Commander, they are playable on turn 3 with this triad

Acceptable Losses Advanced Reconstruction Akroma, Angel of Wrath Avatar Alpharael, Stonechosen Amok Apathy Arcane Bombardment Arcanis, the Omnipotent Avatar Archdemon of Paliano Artillery Enthusiast Balduvian Horde Balor Barbarian Bully Black Cat Blitzwing, Adaptive Assailant Bottomless Pit Bounty of the Deep Burning Inquiry Camouflage Canyon Drake Capricious Efreet Capricious Hellraiser Casey Jones, Vigilante Chaos Defiler Charmbreaker Devils Chef's Kiss Cinderheart Giant Cloak of Confusion Control of the Court Cool but Rude Coral Helm Corrupt Official Cosmium Catalyst Crabomination Cragganwick Cremator Crystalline Giant Cult of Skaro Cursed Scroll Dakkon Blackblade Avatar Deadbridge Chant Dementia Sliver Desperate Ravings Devastating Dreams Do-Over (playtest) Draconian Cylix Drastic Revelation Duelists' Convocation International (playtest) Dwarven Strike Force Eight-and-a-Half-Tails Avatar Elkin Lair Enigma Sphinx Avatar Exalted Flamer of Tzeentch Explosion of Riches Faceless Agent Fervent Mastery Flametongue Kavu Avatar Flay Flowstone Flood Fossil Find Free-for-All Frenetic Ogre Friendly Fire Furnace Layer Gallia of the Endless Dance Gamble Gerrymandering Ghoulraiser Goblin Lore Goblin Secret Agent Goblin Test Pilot Gorex, the Tombshell Greatest Show in the Multiverse

then add Aether Flash, Lightmine Field, and Powerstone Minefield, and go to town
Im never playing Serum Visions into a spot where I need to shuffle a scry to the top, but without pressing needs to play removal or discard, I wouldnt expect that
Glorybringer Glorybringer is one of the best cards in Pioneer, which is no surprise considering how dominant it was in its respective Standard format (after all the ridiculous stuff got banned)