Trait: Ex-Asmodean - Which Devils Worship Asmodeus?

[Lawrence Smith 2]

How does a player/GM determine which devils are vulnerable to the Ex-Asmodean campaign trait?

I picked up a boon at PaizoCon that enables me to select a trait from the Hell's Rebels Player's Guide.

Hell's Rebels Player's Guide wrote:

Choose one: you gain a +1 trait bonus on attack rolls and weapon damage rolls or you gain a +1 trait bonus on the save DCs of your spells against agents of House Thrune and worshipers of Asmodeus, including most (but not all) devils.

If a devil worships Asmodeus, then the trait applies. However, bestiary entries for devils don't indicate whom they worship.

Thanks for your help.

[Blake's Tiger]

It means most of all types of devils worship Asmodeus, but individual devils (by design of the AP or GM) might not.