Tzu, Stratagem Masterworker

At the beginning of your upkeep, remove all
sword counters and shield counters from
creatures. Then, for each creature you don't
control, that creature's controller puts either a
sword counter or a shield counter on it.
Creatures with shield counters on them can't
attack and must block each combat if able.
Creatures with sword counters on them can't
block and are goaded.