Kostroq, Horned Champion

Double strike, horns (Whenever a source you
control deals damage to an opponent, this
creature gets +1/+1 until end of turn.)
{b}{r}{r}: Kostroq, Horned Champion deals 1
damage to target opponent. Activate this ability
only once each turn.
"If you dodge the first swing of the axe, watch
out for its second."
— Adrel, first sword of the order