Brimstone says when a card is discarded from an opponents hand choose a character that character loses an icon. Does this mean that if I have a 2 claim plot and win an intrigue challenge I can respond with brimstone twice or does my opponent discard both cards at the same time so I can only respond once?

Each discarded card creates a separate response opportunity, even if they are discarded by a single effect. The wording of The Brimstone allows you to trigger once per discarded card.

I believe this equates to the same thing with military claims - i.e. if 2 lords die for a single military claim and I have the Joffrey who can claim a power each time a lord or lady dies, I can claim 2 power ... the fact that the 2 characters die simultaneously is not a factor

But it is not the same for power challenges?

If someone wins a 2 claim power challenge they claim 2 power in one hit and I can take both powers with Infamous?

If someone wins a 2 claim power challenge they claim 2 power in one hit and I can take both powers with Infamous?

Infamous! doesn't work at all on power won from claim, because that power isn't actually "claimed," it's "moved" to your house card.

Additionally, Infamous! specifically says "after a player claims 1 or more power," so it is looking at the results of a single initiated "claim" effect, not at when a power token is claimed.

If The Brimstone said "after a player discards 1 or more cards from had," then you'd only get to trigger it once per discard effect, rather than once per card discarded.

thanks - that old chestnut that power "moved" as the claim for a power challenge is not claimed!!!

(ran into that with the Siege agenda)