Before I get into the power of Blood Tokens, let us have a look at what a Blood Token is
Alpharael, Dreaming Acolyte Ancient Excavation Architects of Will Carlo, Suave Schemer Clutch of the Undercity Cyclonus, the Saboteur Dihada's Ploy Dimir Infiltrator Dire Undercurrents Disciple of Deceit Dreadwing Scavenger Emet-Selch, Unsundered Evangel of Synthesis Great Intelligence's Plan Horrid Shadowspinner Jhessian Zombies Kaito Shizuki Kang, Temporal Tyrant Katara, Seeking Revenge Lazotep Chancellor Likeness Looter Locke Cole Mob Lookout Obsessive Stitcher Oskar, Rubbish Reclaimer Perplex Prowler, Clawed Thief Psychatog Psychic Frog Shadowstorm Vizier Soul Ransom Tainted Indulgence The Ancient One Tiger Shark, Abyssal Hunter Tomebound Lich Ultron, Unlimited Unfulfilled Desires Vohar, Vodalian Desecrator
Is that good enough for taking the turn off
There are so many ways to completely break Skullclamp that it had to be banned in Modern and Legacy, but you can still use and abuse it in Vintage and Commander