I think we should discard 20 pends,2 Skull Shields, and 2 Plagues.
We need to keep our Light cards because I think we'll want to use this in later rounds. If teams don't expect a stall, this deck can usually win. We can afford to discard 20 pends because we can convert 24 cards to pends if we absolutely have to. If we discard 2 Plagues and 2 Shields, we now have 12 Plagues and 4 Skull Shields. It's enough to run this deck again and also allows us to have enough Plagues to use in other decks.