[Morthoron]

Turin may well be a hero in the formula of a classic Greek tragedy, however, the parallels favor Kullervo rather than Achilles as far as the story goes.

There are many Tolkien characters who are near perfect examples of heroes from Greek tragedies -- in addition to Turin, Boromir for instance. They exhibit the four principal characteristics of a tragic hero: 1. the character is of noble birth, 2. He has a tragic flaw (hamartia), 3. He has a reversal (a catastrophe), and 4. he undergoes a catharthis, or recognition, a realization of his own flaw that caused his reversal. And, as is usual in Greek tragedy, his recognition comes too late to prevent his succumbing to the reversal.

But again, Turin's story is essentially derived from the Kalevala, and the self-destructive, often berserk character Kullervo, right down to being born in bondage, unknowingly seducing his sister and dying on a sword that willingly takes his life (and says so).