Say you are drafting a deck in which you know you want around 16 creatures (a pretty standard number for most drafts, though one that can vary widely by format and archetype)
The mysterious signature appeared again and again, on some highly desirable cards
Aboshan, Cephalid Emperor Acquisition Octopus Backstreet Bruiser Bubble Smuggler Caelorna, Coral Tyrant Callous Oppressor Cephalid Aristocrat Cephalid Broker Cephalid Constable Cephalid Facetaker Cephalid Illusionist Cephalid Inkmage Cephalid Inkshrouder Cephalid Looter Cephalid Pathmage Cephalid Retainer Cephalid Sage Cephalid Scout Cephalid Snitch Cephalid Vandal Crafty Octopus Elder Deep-Fiend Giant Octopus Godhunter Octopus Kamiz, Obscura Oculus Keen Buccaneer Llawan, Cephalid Empress Lorthos, the Tidemaker Lorthos, the Tidemaker Marvo, Deep Operative Mesmerizing Benthid Obscura Interceptor Octavia, Living Thesis Octoprophet Omen Hawker Psychic Pickpocket Purple Pentapus Queza, Augur of Agonies Revel Ruiner Sea-Dasher Octopus Sealock Monster Shark Shredder, Killer Clone Sharktocrab Shield Broker Tidal Terror Ultros, Obnoxious Octopus Unruly Krasis
At two auras, it gains vigilance and becomes a 5/5
Since all the key cards are dirt cheap the deck ends up dominating even on an extremely low budget
