Agreed with Ringbearer. Conditions to be discarded by
DiT /
FNF simultaneously enter the "about to be discarded" stage, at which point
Deceit can respond to each (except itself by its own text), preventing it from being discarded. As for
BRC, the way I see it, it passes the "If a Free Peoples player's card is about to..." check on
Deceit, so
Deceit can prevent those discards as well.
Blood Runs Chill says make a shadow player discards... I thought Deceit only worked if the freepeople player's card directly targets a shadow condition. I might be mistaken but if the shadow players chooses a Gollum condition in that situation, I always thought Deceit would not be able to prevent it.
BRC is making the Shadow player do the discarding, which I don't think matters for
BRC, but would for something like
Siege Engine (which checks for "about to be discarded by an opponent"). There are at least checks for if discarding is done by a FP/Shadow card, which player is doing the discarding, if a card is "making" a player discard, etc.