Chamber Tracer

Creatures with flowstone counters on them get
-3/-0, have shroud, can't be blocked, and can't
block.
Whenever a creature you control attacks and isn't
blocked, defending player loses half of their life,
rounding down. You and they each add {e}.
{p/c}, {e}, Discard a card: Scri 2, then draw a card.
Put a flowstone counter on each of up to two
target creatures.