Well, I havent seen many Renekton players out there lately and when i do, they all seem to build tankish or VERY weak dps, rendering them to have almost no existence in the game. Therefore, this dps build for Renekton not only increases your significance in the game, but also your overall intimidation. DPS Renekton is back baby!

The runes speak for themselves. By taking early damage output advantage with flat attack damage marks, you're sending a strong message to your enemies: "I can and will kill you." Indimidation with Renekton is key IMO, and never be afraid to jump right into a fight and initiate someone even though their health is full.
By giving yourself flat health runes, you're giving yourself more room to work with during laning and fighting. More health = more existence in the lanes. Harass more than your enemies can, stunning one every chance you get and culling right after.
Though it may seem like a waste, glyphs of malice do play a huge role in your ability to deal damage even when your abilities are on cooldown. DO NOT RELY ON RENEKTONS ABILITIES. thats what gets you killed. DPS physical attacks should be split half and half with your abilities, allowing you to not rely on abilities, but also using them at the exact moment you need them.
The quintessences speak for themselves.

The offensive masteries go with how he's supposed to be played: a dps beast. With cooldown reduction, armor penetration, and increased damage overall, you'll be dealing the greatest amount of damage out of all players in the game at level 1!

The items i have come up with for renekton allow him to not only deal damage, but stay alive and chase people if needed. The lucidity boots of course for cooldown reduction, The Bloodthirster for added damage and great lifesteal stacking, the phantom dancer for attack and movement speed, not to mention critical strike, the infinity is a must on renekton, almost half of your power is coming from this item, sunfire cape, for health and armor and overall more durability, and the youmuus: more cd and more crit chance, plus armor penetration.

Allowing yourself maximum damage output is a must for renekton, even if you are low leveled or fed like none other. taking turns maxing Cull the Meek and Ruthless Predator can greatly increase your damage output, only leveling slice and dice once, allowing you to either chase or run, depending on your situation.