Ramping damage, lifesteal/sustain, and scaling ramp damage.
Improved attacks and sustained damage
Attacking a champion 3 times will expose them, dealing bonus damage and causing them to take more damage from all sources for 6 seconds.
Excess healing on you becomes a shield.
Takedowns on enemies grant permanent Attack Speed.
Deal 7% more damage to low health champions. Gain AD/AP after kills or assists.
9% attack speed, 10 ability power or 6 attack damage
While above 70% health, gain up to +40 Ability Power or +28 Attack Damage (based on level), Adaptive.
Gain increasing amounts of AD or AP, Adaptive over the course of the game.
Press the Attack's exposure damage synergizes incredibly well with BotRK + Black Cleaver + [R] shredding even the tankiest champions.
Overheal is a great rune for topping off your heal to sustain chip damage from the enemy, and synergizes well with the Life Steal from BotRK and Bloodline.
More Attack Speed simply means more damage per second output, especially in elongated teamfights where you are able to get several off.
Coup De Grace is a great rune for finishing of the last bit of health on champions you have shredded with Black Cleaver and Press the Attack.
Absolute Focus' raw AD value grants you the ability to trade aggressively and pump out damage from behind your support as well as last-hit more effectively in lane thanks to the additional AD.
Gathering Storm is your late game insurance policy. Paired with Press the Attack, your late game single target dueling damage will be massive.