Wizards R&D has repeatedly tried to get a combine your creatures mechanic right, and after the success of host/augment in Unstable, it seemed they were getting close
In most cases, it's a 6/6 Phyrexian Wurm the first time, and a 10/10 Phyrexian Wurm when you cast Wurmquake with flashback
A holo version of the card sold for $70,000 in a 2021 PWCC auction

Izzet Guildmage Izzet Guildmage | Illustration by Jim Murray Commander (1) Creature (7) Oliphaunt Automated Artificer Fallaji Archaeologist Ornithopter of Paradise Academy Wall Trinket Mage Murmuring Mystic Instant (31) Brainstorm Consider Dispel Electrickery Fiery Impulse Frost Bite Galvanic Blast Gigadrowse High Tide Intervene Lightning Bolt Opt Skred Arcane Denial Blink of an Eye Counterspell Deprive Dramatic Reversal Fire / Ice Fire Prophecy Impulse Into the Roil Memory Lapse Moment of Truth Muddle the Mixture Negate Radical Idea Think Twice Thrill of Possibility Volcanic Spite Dizzy Spell Sorcery (9) Gitaxian Probe Hard Evidence Lrien Revealed Ponder Preordain Treasure Cruise Cleansing Wildfire Hidden Strings Merchant Scroll Enchantment (1) Artifact (18) Everflowing Chalice Arcum's Astrolabe Moonsnare Prototype Relic of Progenitus Springleaf Drum Arcane Signet Fellwar Stone Izzet Signet Neurok Stealthsuit Sky Diamond Star Compass Bonder's Ornament Honored Heirloom Lantern of Revealing Network Terminal Firemind Vessel Sisay's Ring Ur-Golem's Eye Land (33) Ash Barrens Command Tower Evolving Wilds Great Furnace Izzet Boilerworks Maestros Theater Molten Tributary Mystic Sanctuary Prismari Campus Silverbluff Bridge Snow-Covered Island x17 Snow-Covered Mountain x4 Terramorphic Expanse Volatile Fjord The cycles of Guildmages from the various Ravnica sets have always made for good uncommon commanders

Thickness of 1 Side (microns): Vault X Exact Fit (60), Gamegenic Prime (105) 100 Double Sleeved Card Thickness (mm): Theoretical (63), Practical (68) Water Test: Pass Deck Box Fit (mm storage): Fit: 99 good, 1 bad
While it has frequently been maindecked, its also been a popular sideboard card, perfect for grinding out attrition-based post-sideboard games, such as the Kithkin deck Cedric Phillips piloted to a top 8 finish in PT Kyoto 2009: Creatures (20) Planeswalkers (4) Lands (25) Spells (11) Sideboard Nowadays, the idea of aggro decks slowing down and going bigger after sideboarding is commonplace, but Cedrics use of it here was especially futuristic for that time period