43 cards where the set is “who” and the collector number >= 535 and the collector number <= 564

Rose Tyler (Doctor Who #535)
Sarah Jane Smith (Doctor Who #536)
K-9, Mark I (Doctor Who #537)
Dalek Squadron (Doctor Who #538)
Yasmin Khan (Doctor Who #539)
Davros, Dalek Creator (Doctor Who #540)
The Fugitive Doctor (Doctor Who #541)
The Master, Formed Anew (Doctor Who #542)
The Master, Gallifrey's End (Doctor Who #543)
The Master, Mesmerist (Doctor Who #544)
The Master, Multiplied (Doctor Who #545)
Missy (Doctor Who #546)
River Song (Doctor Who #547)
The War Doctor (Doctor Who #548)
Weeping Angel (Doctor Who #549)
Cyberman Patrol (Doctor Who #550)
TARDIS (Doctor Who #551)
The First Doctor (Doctor Who #552)
The First Doctor (Doctor Who #552z)
The Second Doctor (Doctor Who #553)
The Second Doctor (Doctor Who #553z)
The Third Doctor (Doctor Who #554)
The Third Doctor (Doctor Who #554z)
The Fourth Doctor (Doctor Who #555)
The Fourth Doctor (Doctor Who #555z)
The Fifth Doctor (Doctor Who #556)
The Fifth Doctor (Doctor Who #556z)
The Sixth Doctor (Doctor Who #557)
The Sixth Doctor (Doctor Who #557z)
The Seventh Doctor (Doctor Who #558)
The Seventh Doctor (Doctor Who #558z)
The Eighth Doctor (Doctor Who #559)
The Eighth Doctor (Doctor Who #559z)
The Ninth Doctor (Doctor Who #560)
The Ninth Doctor (Doctor Who #560z)
The Tenth Doctor (Doctor Who #561)
The Tenth Doctor (Doctor Who #561z)
The Eleventh Doctor (Doctor Who #562)
The Eleventh Doctor (Doctor Who #562z)
The Twelfth Doctor (Doctor Who #563)
The Twelfth Doctor (Doctor Who #563z)
The Thirteenth Doctor (Doctor Who #564)
The Thirteenth Doctor (Doctor Who #564z)

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