34 cards where the set is “por” and the card has been printed exactly once

Capricious Sorcerer (Portal #43)
Charging Bandits (Portal #84)
Cloud Pirates (Portal #46)
Craven Knight (Portal #85)
Cruel Fate (Portal #50)
Deep-Sea Serpent (Portal #51)
Defiant Stand (Portal #12)
Desert Drake (Portal #122)
Djinn of the Lamp (Portal #52)
Dread Charge (Portal #88)
Final Strike (Portal #94)
Fire Snake (Portal #127)
Fleet-Footed Monk (Portal #15)
Fruition (Portal #166)
Highland Giant (Portal #132)
Keen-Eyed Archers (Portal #19)
Mercenary Knight (Portal #99)
Mind Knives (Portal #100)
Minotaur Warrior (Portal #140)
Raging Cougar (Portal #144)
Renewing Dawn (Portal #23)
Rowan Treefolk (Portal #184)
Sacred Knight (Portal #24)
Scorching Winds (Portal #149)
Skeletal Crocodile (Portal #110)
Skeletal Snake (Portal #111)
Stern Marshal (Portal #32)
Taunt (Portal #71)
Thundering Wurm (Portal #189)
Treetop Defense (Portal #190)
Undying Beast (Portal #113)
Valorous Charge (Portal #34)
Vampiric Touch (Portal #115)
Warrior's Charge (Portal #38)

This search is finished. Now the real work can begin.