Shadow Blade

The Shadow Blade is an Item purchasable at the Main Shop, under Weapons.

Shadow Walk
Makes you invisible until the duration ends, or until you attack or use an ability. While invisible you move 20% faster and can move through units. Has a 0.3 second fade time. Attacking to break the invisibility will cause you to deal 150 bonus physical damage on your attack. Lasts 9 seconds, costs 75 mana, and has an 18 second cooldown.

Trivia

 * In the original DotA, this item was called Lothar's Edge.