Duskblade of Draktharr

Razor:+15 Armor Penetration.

Nightstalker:  Being unseen for 1 second causes your next basic attack against a champion to deal 20 – 125 bonus physical damage and slows them by 99% for 0.25 seconds. Buff lasts for 5 seconds if you are in the view of one enemy, and ranged attacks do not slow enemies.