33 cards where the set is “one” and the text includes “proliferate”

Adaptive Sporesinger (Phyrexia: All Will Be One #157)
Blightbelly Rat (Phyrexia: All Will Be One #85)
Bloated Contaminator (Phyrexia: All Will Be One #159)
Cacophony Scamp (Phyrexia: All Will Be One #124)
Cankerbloom (Phyrexia: All Will Be One #161)
Carnivorous Canopy (Phyrexia: All Will Be One #162)
Contagious Vorrac (Phyrexia: All Will Be One #164)
Copper Longlegs (Phyrexia: All Will Be One #165)
Drown in Ichor (Phyrexia: All Will Be One #91)
Expand the Sphere (Phyrexia: All Will Be One #168)
Experimental Augury (Phyrexia: All Will Be One #49)
Ezuri, Stalker of Spheres (Phyrexia: All Will Be One #201)
Gitaxian Anatomist (Phyrexia: All Will Be One #52)
Gulping Scraptrap (Phyrexia: All Will Be One #96)
Ichormoon Gauntlet (Phyrexia: All Will Be One #56)
Mesmerizing Dose (Phyrexia: All Will Be One #62)
Reject Imperfection (Phyrexia: All Will Be One #67)
Scheming Aspirant (Phyrexia: All Will Be One #107)
Serum Snare (Phyrexia: All Will Be One #68)
Staff of Compleation (Phyrexia: All Will Be One #242)
Tainted Observer (Phyrexia: All Will Be One #217)
Tekuthal, Inquiry Dominus (Phyrexia: All Will Be One #71)
Thirsting Roots (Phyrexia: All Will Be One #185)
Thrummingbird (Phyrexia: All Will Be One #72)
Unnatural Restoration (Phyrexia: All Will Be One #191)
Vat Emergence (Phyrexia: All Will Be One #112)
Venomous Brutalizer (Phyrexia: All Will Be One #193)
Venser, Corpse Puppet (Phyrexia: All Will Be One #219)
Vivisurgeon's Insight (Phyrexia: All Will Be One #77)
Voidwing Hybrid (Phyrexia: All Will Be One #221)
Volt Charge (Phyrexia: All Will Be One #155)
Vraska, Betrayal's Sting (Phyrexia: All Will Be One #115)
Whisper of the Dross (Phyrexia: All Will Be One #117)

The message was clear to Sorin—time to search for something else.