-Slice and Dice excels at harassing maneuvers. Slice in, follow up with another skill and then Dice back out to safety. Ussualy pick Cull The Meek , the second skill after Slice and Dice.

-Cull the Meek drains an enormous amount of life when used in the middle of the fray. You can use this to bait opponents into thinking you are weaker than you really are.

Renekton is a mele dps champion.
For this build you are going to play him as a dps/tank, in eary game dooing thounds of damage and late game verry rezistent in team fights and verry good pusher.

Picked this masteris for Attack Damage bouns and harrasing enemy team.

Dps in early.. you don't need so much atack speed your relying on your skills.

Farming minions is verry easy and will help you get your expensive build done in no time!
Also change the Warmog's armour with an Frozen Mallet.

I consider attack damage runes verry usefull in early game ..harrasing like hell.

In a 1v1 your exhaus will grant you 100% win and its good for chasing and escaping too.
Ghost it's a must have spell for towerdiving and other chases.

Pros:
-Stun.
-High damage early.
-Great farmer.
-Good escaper.
-Carry , dont need to go b often.
Cons:
-Early sqishy.. (no matter in late)
-Easy focused.

With this build not only that you will survive and have low Deaths you are going to do thounds of damage and help your team.

1)
Cull the Meek - Renekton swings his blade, dealing moderate physical damage to all targets around him and heals for a small portion of the damage dealt. If he has more than 50 Fury, his damage and heal are increased.
Renekton swings his blade, dealing 60/90/120/150/180 (+) physical damage to nearby enemies and gains 5% of the damage dealt as Health, up to 50/75/100/125/150. Each hit grants 5 Fury, up to 25. Enemy champions grant 300% additional health recovery.

50 Fury Bonus: Damage increased to 90/135/180/225/270 (+). Heal percent increased to 10%, up to 150/225/300/375/450.
Conclusion: Use it anytime to regain your health.
2)
Ruthless Predator - Renekton slashes his target twice, dealing moderate physical damage and stuns them for 0.75 seconds. If Renekton has more than 50 Fury, he slashes his target three times, dealing high physical damage and stuns them for 1.5 seconds.
Renekton's next attack strikes twice, dealing physical damage (10/30/50/70/90 + 150/150/150/150/150% of his Attack Damage) and stuns for 0.75 seconds. Each hit applies on-hit effects.

50 Fury Bonus: Instead, Renekton attacks three times, dealing physical damage (15/45/75/105/135 + 225/225/225/225/225% of his Attack Damage) and stuns his target for 1.5 seconds.
Concusion: Really great damage in early game you take half hp on sqishy targed with this.
3)
lice and Dice - Renekton dashes, dealing damage to units along the way. Empowered, Renekton deals bonus damage and reduces the armor of units hit.
Slice: Renekton dashes, dealing 30/60/90/120/150 (+) physical damage. Hitting an enemy grants the ability to use Dice for 4 seconds.

Dice: Renekton dashes, dealing 30/60/90/120/150 (+) physical damage.

Dice - 50 Fury Bonus: Damage increased to 45/90/135/180/225 (+). Enemies hit have 15/17.5/20/22.5/25% reduced Armor for 4 seconds.
Conclusion: Good for harras and verry good escaping skill
ULIMATE:
Dominus - Renekton transforms into the Tyrant form, gaining bonus Health and dealing damage to enemies around him. While in this form, Renekton gains Fury periodically.
Renekton surrounds himself with dark energies for 15 seconds, gaining 300/450/600 Health. While active, he deals 40/70/100 (+0.1) magic damage to nearby enemies and gains 5 Fury per second.
Conclusion: Use it when the fight its ready to start. With this skill at lvl 6 you can tower dive for the kill and escape very easy.

Passive:
Reign of Anger - Renekton gains Fury for every autoattack he makes. This Fury can empower his abilities with bonus effects. Additionally, Renekton gains bonus Fury when he is low on life.
Best way to use your skills it's when you gathered 50 fury. When enemy players see you low hp and think your weak they won't realizise that your stronger than from the firstlook.