19 cards where the full Oracle text includes “specialize”

Alora, Rogue Companion (Alchemy Horizons: Baldur's Gate #5)
Ambergris, Citadel Agent (Alchemy Horizons: Baldur's Gate #12)
Gale, Conduit of the Arcane (Alchemy Horizons: Baldur's Gate #6)
Gut, Fanatical Priestess (Alchemy Horizons: Baldur's Gate #13)
Imoen, Trickster Friend (Alchemy Horizons: Baldur's Gate #7)
Jaheira, Harper Emissary (Alchemy Horizons: Baldur's Gate #16)
Karlach, Raging Tiefling (Alchemy Horizons: Baldur's Gate #14)
Klement, Novice Acolyte (Alchemy Horizons: Baldur's Gate #1)
Lae'zel, Githyanki Warrior (Alchemy Horizons: Baldur's Gate #2)
Lukamina, Moon Druid (Alchemy Horizons: Baldur's Gate #17)
Lulu, Forgetful Hollyphant (Alchemy Horizons: Baldur's Gate #3)
Rasaad, Monk of Selûne (Alchemy Horizons: Baldur's Gate #4)
Sarevok the Usurper (Alchemy Horizons: Baldur's Gate #9)
Shadowheart, Sharran Cleric (Alchemy Horizons: Baldur's Gate #10)
Skanos, Dragon Vassal (Alchemy Horizons: Baldur's Gate #18)
Vhal, Eager Scholar (Alchemy Horizons: Baldur's Gate #8)
Viconia, Nightsinger's Disciple (Alchemy Horizons: Baldur's Gate #11)
Wilson, Bear Comrade (Alchemy Horizons: Baldur's Gate #19)
Wyll, Pact-Bound Duelist (Alchemy Horizons: Baldur's Gate #15)

The arc of my blade has carved a path of light to the end of these results.