Both Cassandra in "The Oresteia" by Aeschylus and Tireisias in "Oedipus Rex" by Sophocles are prophets with an authentic gift of prophecy. In both cases though, the gift is a mixed blessing, because it is mixed with a curse. In the case of Tireisias, although he sees the true future, he is blind, and cannot see the world around him. In the case of Cassandra, the god Apollo granted her the gift of prophecy, but also cursed her with the fate that she would never be believed, as Cassandra herself described in her monologue in the "Agamemnon", the first play in The Oresteia trilogy:
They call me crazy, like a fortune-teller,
A poor starved beggar-woman - and I bore it!
And now the prophet undoing his prophetess
Has brought me to this final darkness.
Two obvious differences between the characters are age and gender -- Tireisias is an old man and Cassandra a young women. Another major difference between the characters is that Tireisias is more honoured than Cassandra and is still alive at the end of "Oedipus Rex", while Cassandra, a dishonoured war prize, is killed by Clytemnestra.