Rallying the Troops

When Rallying the Troops enters the battlefield,
you become the Master (monarch).
At the beginning of combat on each opponent's
turn, if you're the master, that opponent may
pay {x}, where X is the number of cards in their
hand. If they don't, they can't attack you this
combat.
"200,000 units are ready, with a million more
well on the way" -Lama Su