27 cards where (the card is available on Paper) and the flavor text contains “shakespeare”

Boomerang (Fifth Edition #75)
Castle (Seventh Edition #5)
Cowardice (Ninth Edition #70)
Dark Banishing (Duel Decks Anthology: Divine vs. Demonic #50)
Darkness (Time Spiral Timeshifted #40)
Devouring Deep (Legends #50)
Early Harvest (Ninth Edition #235)
Ebon Dragon (From the Vault: Dragons #6)
Exalted Angel (Judge Gift Cards 2006 #1)
Fireslinger (Friday Night Magic 2002 #6)
Firestorm Phoenix (Legends #147)
Gaseous Form (Fifth Edition #90)
Giant Strength (Classic Sixth Edition #181)
Jackal Pup (Friday Night Magic 2001 #8)
Moon Sprite (Starter 2000 #42)
Naturalize (Eighth Edition #270)
Pay No Heed (Magic 2014 #27)
Pernicious Deed (Judge Gift Cards 2006 #4)
Redeem (Eighth Edition #37)
Shimian Night Stalker (Chronicles #36)
Sol Ring (Secret Lair Drop #1696)
Squall (Seventh Edition #271)
Thespian's Stage (Doctor Who #323)
Tidings (Starter 1999 #54)
Winter Blast (Fifth Edition #343)
Wolverine Pack (Fifth Edition #344)
Wrath of God (Portal #39)

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