Legion Commander has the amazing ability to survive even the toughest right-clicker onslaughts thanks to her Moment of Courage ability. To use this build effectively, you will need to be comfortable with using multiple spells and active items in quick succession, and be familiar with Blink Dagger (or alternatively, Shadow Blade) and Armlet toggling.
You can either jungle or lane early game, but make sure you gank mid game to snowball with Duel. The main combo is: Armlet on, self cast PTA, Blink, Duel.