If a creature has multiple instances of afflict, each triggers separately.
May 3, 2019 · War of the Spark
Ascend on a permanent represents a static ability. It means “Any time you control ten or more permanents and you don’t have the city’s blessing, you get the city’s blessing for the rest of the game.”
January 25, 2019 · Ravnica Allegiance
Ascend on a permanent represents a static ability. It means "Any time you control ten or more permanents and you don't have the city's blessing, you get the city's blessing for the rest of the game."
January 19, 2018 · Rivals of Ixalan
Ascend on a permanent represents a static ability. It means “Any time you control ten or more permanents and you don’t have the city’s blessing, you get the city’s blessing for the rest of the game.”