The Prowler's Claw's only use is to E+Prowler's. Doing this will put you in a very dangerous position. You will separate yourself from your team by doing this combo. Even if you kill the target there will be no escape tool for you. (Don't say W, because most of the time you will start this combo with your W.) After that either the teamfight will start or you will die before your team arrives.

This item only good against split pushers with no escape skill or against "no team fight, only farm" ADC's which is already behind and trolling the game. (Basically no one)

You should buy Draktharr most of the time.

PRIMARY RUNES

Ultimate Hunter: Standard (if you are mid only option is this)
Relentless Hunter: For more roaming. If you take this buy Ionian boots.
Treasure Hunter: Early snowball. (Not worth for lower ranks)
Ingenious Hunter: If you will buy Prowler's and try to assasinate carries.

SECONDARY RUNES

RESOLVE

Second Wind: vs Poke
Bone Plating: (doesn't have much use in mid) vs all in matchups. (vs Draven, Kai'Sa, Nautilus, Thresh, etc.)


Unflinching: 99% of the time.
Revitalize: Only vs if the enemy team has no cc or slow and you need Second Wind.

PRECISION

Standard Precision Tree runes if you believe you can snowball. Best runes for teamfights but worst for lane.

INSPIRATION

Only for support if you are gonna buy Prowler's or for Gold Efficieny (Combine:Treasure Hunter,Free Boots,Debt)

Cosmis Insight: Item Haste (Prowler's, GA, EoN, Maw)
Biscuit: Survivability
Future's Market: Gold Efficiency
Free Boots: Gold Efficiency