Fus Ro Dah

(A Thu'um can have a maximum of 3 soul counters
on it)
{2}: Put a soul counter on Fus Ro Dah. Activate
this ability only during your turn and only once
each turn.
{4}: Tap up to X nonland permanents where X is
the number of soul counters on Fus Ro Dah.
Those permanents don't untap during their controller's next untap step.