Gyarados, The Atrocious

Whenever Gyarados blocks a creature, that creature gets -1/-1 until end of turn.
{u}, {t}: Put a +1/+1 counter on Gyarados at the beginning of your next upkeep.
{b}{b}, {t}: Gyarados deals 3 damage to target creature.
{2}{r}: Gyarados gets +2/+0 and gains first strike until end of turn.
{4}{u}, {t}: Return up to three target creatures to their owner's hand.