Place 4 power counters on Plascrete Carapace when it is installed. When there are no power counters left on Plascrete Carapace, trash it.
Hosted power counter: Prevent 1 meat damage.
Plascrete Carapace is a hard counter to the common and dangerous card Scorched Earth, and the related SeaScorch strategy. Many, many runner decks include 2-3 copies Plascrete Carapace to combat it, although other runner strategies do exist to combat Scorched Earth without dedicating cardslots to Plascrete Carapace.
What happens if I spend all tokens from Plascrete Carapace and prevent it from being trashed?
Does Plascrete Carapace have constant ability that should be checked in every single moment? Or does this ability mean something like "trash Plascrete Carapace when the last counter's removed"? Plascrete Carapace's trash ability is a conditional ability that continually meets its trigger condition once there are no counters on it, so it would be trashed immediately after it was prevented from being trashed by the Sacrificial Construct.