Dragoon Heart

At the beginning of each upkeep, you may pay {x} and choose a keyword ability. If you do,
creatures you control gain that keyword until
end of turn. If that keyword has a number, that
number is equal to X. (For instance, you may
pay {0} and name Trample, and creatures you
control gain Trample until end of turn. If you
pay {2} and name Ward, creatures you control
gain Ward {2} until end of turn.)