Marco (The Time of Angels)
Cleric Marco was a cleric who went to the Aplan planet, Alfava Metraxis to hunt a lone Weeping Angel. His torch flickered when the Angels interfered with it and he warned Father Octavian. He was later surrounded by the Angels with the Clerics, The Doctor, Amy Pond and River Song. (DW: Time of Angels) Later, he was placed in charge by Octavian to look after Amy. He sent three clerics to investigate a glowing light in an oxygen factory aboard the Byzantium. He forgot about their existence when they were absorbed by the time field and went to investigate for himself leaving Amy alone. Cleric Marco got too close to the light and he was erased from existence. (DW: Flesh and Stone)
When Rory Williams was erased by a time field, Amy remembered that she could still remember the clerics, even though they could not remember each other in the hope she could remember her fiancé. (DW: Cold Blood)
Since the Cracks were sealed off, it's likely that Marco wasn't erased from existence.
