7 cards where the card is tagged “synergy-surveil” and the set is “grn”

Blood Operative (Guilds of Ravnica #63)
Darkblade Agent (Guilds of Ravnica #164)
Dimir Spybug (Guilds of Ravnica #166)
Disinformation Campaign (Guilds of Ravnica #167)
Enhanced Surveillance (Guilds of Ravnica #40)
Thoughtbound Phantasm (Guilds of Ravnica #55)
Whispering Snitch (Guilds of Ravnica #90)

Though this query has ended, its relics still slumber in New Argive.