Fields of Initiation

Landfall —Whenever a land enters the battlefield
under your control, put a prowess counter on up
to one target creature you control. (Whenever you
cast a noncreature spell, that creature gets +1/+1 until
end of turn.)
Whenever you cast your first noncreature spell
each turn, you may pay {1}{w/u}. If you do, put a
+1/+1 counter on each creature with prowess
you control.