Sejuani, Fury of the North

Trample, Endure 3 (At the beginning of your
end step, if a source controlled by an opponent dealt
damage to this creature this turn, put 3 +1/+1
counters on it.)
Whenever Sejuani, Fury of the North attacks, tap
each creature defending player controls with
power less than Sejuani, Fury of the North's
power.
"Trust nothing but your strength."