Cupid, also known as Love, was the equivalent god in Roman mythology to the Greek god Eros. Son of Venus and Mars, he always walked with his bow, ready to shoot the hearts of men and gods. In some interpretations, Cupid could take from his quiver two arrows with opposing effects: an arrow with a rounded tip to inspire hatred, and another arrow with a sharp point to inspire love.
In this case, to make Tybalt hate Romeo, the cupid could have struck Tybalt with an iron arrow using the rounded tip that carries hatred to the heart
"He could have made Tybalt love the Capulets" is the best response since in the ancient scripture and myth Cupid is all powerful in this sense--even giving power to gods.
