His most distinguishing feature is ascribed either to treatment by ambrosia and fire, or being dipped into the river Styx.  
His ghost, along with Helen's, inhabits the island of Leuce on the Black Sea.  He was not bound by the oath of Tyndareus, but rather Calchus prophesized Troy could not fall without this warrior.  Therefore this man hid at Sycros disguised as his sister until Odysseus discovered him by sounding a trumpet.  This son of Thetis and Peleus slew (*) Hector and dragged the body around Troy for nine days.  His most distinguishing feature is ascribed either to treatment by ambrosia and fire, or being dipped into the river Styx.  For 10 points, name this invulnerable Greek warrior with a weakness in his heel.
His ghost, along with Helen's, inhabits the island of Leuce on the Black Sea.  
{Achilles}