Mreguk, Persistent Hunter

Whenever one or more of your opponents are attacked, put a track counter on target land one
of those players control's without a track counter
on it.
Whenever Mreguk Attacks, it gets +1/+1 until
end of turn for each land defending player
controls with a track counter on it. then if that
player controls no lands without track counters on
them Mreguk can't be blocked until end of turn.