Darius is easily one of the most powerful dps champions in the game, but he can't last long with low health. This build relies off of early game kills, and to get these early game kills, you need to outlast your enemy in a fight. With this guide, Darius is not only able to bring down enemies with ease, but he is also able to tank and last in fights.

http://images1.wikia.nocookie.net/__cb20110208224653/leagueoflegends/images/5/58/GMarks_%281%29.png The reason I chose greater strength is because in the beginning of the game Darius will have no AD boost, and may be off by 10 or so damage for that crucial early game kill. Mark of Strength helps to boost that AD without the items early on.
I chose the greater seal of resilience because Darius will not have armor until he builds an Atma's Impaler or Randuin's Omen, middle and late game builds respectively. This Armor boost will improve Darius's defensive capabilities slightly, and can be especially helpful when dealing with drawn out tankvtank fights like Amumu or Shen.

I prefer the greater glyph of focus because Darius is all about his Hemorrhage effect stacking. This bleed can be comboed with his highly damaging abilities, but early in the game, his killing power is very limited by cooldowns, especially in Decimate and Apprehend.

I prefer the Quintessence of Alacrity because it simply gives Darius more killing power. The attack speed boost it gives can make that 1-hit difference in a crucial early game kill, and I find it very useful.

I am not going to go in-depth on every mastery I chose, mainly because most of them are self explanatory, but many people will see DPS and expect a 21-9 setup. The main function of this build however, is to be a tank, so I have gone 9-21. This is a popular setup for this build and I find it maximizes the way Darius is played as a tank.

Almost all of the damage Darius does will come from his Q, it affects a large area and does massive amounts of damage that are added to as your AD increases. Instead of getting his W at level two, however, i decided to get his E, Apprehend. The combo of a quick Apprehend, Decimate, and ignite is deadly at long ranges, and can easily pick a weak enemy champion out of the crowd. Although the E is important for kills, etc., Darius does the most damage per strike with his W, which is a modified basic attack. This attack is great to start off or finish the bleed stacks on an enemy champion before going in for the kill with Noxian Guillotine. In my opinion Noxian Guillotine is one of the most overpowered ultimates in the game. However, DO NOT USE IT IF YOUR TARGET IS NOT BLEEDING! This attack will only do serious damage if you have bleed stacks on the target. I would reccomend having at least two bleeds before even attempting to use your ultimate.

I prefer flash and ignite over any other summoner spells, but if you do not have either, ghost is a viable substitute for flash and surge can replace ignite. The flash is crucial in chasing down those enemies that think they are too fast for "Slow, OP Darius", flash will make them think again, bringing them into range of your E, where you can combo them out for the quick and neat kill. Ignite is great for those kills that your ulti just won't reach. Say you need to kill an enemy around 100 hp that is just outside of the range of your Noxian Guillotine. Ignite has a much larger range, and can easily take down an enemy on the run with 100 health, especially if your bleed effect is stacked with them.

Pros Cons
Very quick early game kills Very low mana(Philosopher's Stone 1st)
Huge threat late game Very expensive and Long Build
Very "situational build" Weak vs Long Range(Caitlyn)[Thornmail Counter]
(Black Cleaver only needed
if they have a tanky team)

Thank you very Much for reading! I love all feedback, especially since this is my first guide. Please let me know of any "tweaks" you know and I will patch them in. I hope you enjoyed and there may be more to come.