This is mainly an item build. I use them almost every game and range around 20 kills with around 2-3 deaths. It's very helpful to me and I thought I ought to share it with other people.

You Should usually start off with a Doran's shield whether you are going top lane or bottom lane. It gives you great sustain and allows you to stay in your lanes longer early game and farm up. Next build boots, and follow that with a Phage. Phages give you health and it slows enemies that are running away from you. After seeing who the main source of damage is on the enemy team build mercury treads if they are AP or build Ninja tabi if they are AD or if you are going attack you might want to build Ionian boots of Lucidity so you can spam your Q all day baby. Right after that you should finish the Phage and build frozen mallet, for its health, attack and unique passive. A complete tank is never good so you should start building a blood thirster for late game which can give up to 100 attack, but don't rush it. Build more HP with warmogs, at this point you should be tanking most of the damage for the team, you will be focused in team fights because you will be dishing out a lot of damage so the enemy team will want you gone. Next, build some more attack but follow with a Warden's chain mail. Wardens chain mail will help you when you get 3-5 man ganked. It is great crowd control because it slows the attackers attack speed and movement speed allowing you to either get away or fight back. Finish up the blood thirster and quickly try to farm up 40 minions. Next finish the wardens chain mail into the Randuin's Omen. It gives you good health and armor. Its passive and active are great and will get you out of many sticky situations like the entire enemy team focusing you. Sell the doran's shield and buy a guardians angel. This reassures your invincibility. Not only does it give you a lot of magic resist and armor but its Passive is insane. The off tank build is about the same as the Tank build but minus a few HP and you plus a lot of attack. As the last item you should sell the heart of gold for an atma's impaler because with all the kills you will be getting you don't need no chump change 10 gold every 5 seconds. Also for off tank you could try Ionian boots of lucidity.

This is mainly just an items build. Darius is pretty easy to use so I don't think I need to go into all the super combos or anything sooooooo have fun and kill some noobs. If you really want a move combo try Q-E-W-Q then a bunch of auto attacks, and always remember use your Ultimate to kill steal everyone.