Based on the current errata for Brass Serpent,
Errata:
Discard all poisons and diseases in play. Heal all Heroes in play.
and how heal works,
A character is healable if it is about to be discarded, was discarded earlier in the same turn, is poisoned, or is diseased. If no more specific requirement is specified targets must be healable.
1) Can Brass Serpent heal heroes that are, "about to be discarded", but not heroes previously discarded in the same turn because it specifies that the heroes have to be in play?
2) Are heroes that are "about to be discarded" even considered in play?
Unrelated,
I couldn't find anywhere in the Redemption Wiki or REG that cards return to face value/reset in discard pile. If someone could point out where I can find this information that would be much appreciated.