Check out H4xDefender's guide if you haven't already. It's outdated, but so is this guide. The problem with writing a guide is that you really need more in-depth information. I don't mean to say you have to write a book, but when you state things, they have to be accurate. (maxed E is 25% apen, not 35% and flat apen isn't subtracted from armor, there is a formula.. armor is slightly better than apen, otherwise you might as well go full apen quint/marks) I'm not trying to troll/be a ****, just giving my pov on the guide. This is the #1 reason I haven't written a guide myself. There is a lot of information I am lacking and I don't want to misinform anyone. There are good things here, but if you look at the link above... you'll see it's a one shop stop with great explanations about anything and everything you'd ever want to know about Darius.

Thank you for your comment, I am always open to ways to help improve. But to answer your few questions:
1. I find Guardian Angel necisarry because not only does it bring you back to life in teamfights (Which can turn fights around, since not only do you soak in the damage, you deal a lot as well) it gives you +50 Armor and +40 MR. Very useful if you ask me, but it's a personal preference, honestly.
2. Those are good for some people, but I prefer 4 Ar. Pen and 5 AD. Again, personal preference, but I will add these both in.
3. From what I've seen, no. Q is your primary harass, and although your W does 200% total damage when maxed, (in cases I've seen, might not always be the case) Q does more damage. The slow is mostly for CC, even though it is somewhat personal preference, I think maxing Q is better.
4. Being the noob I am at making builds (this is my first) I comepletely overlooked the summoner spells. Will work on it immediatly.
5. As I said in the begining, this wasn't very in-depth, mostly basic, but there was a lot of information I missed out on. Will work on making it more detailed.


Thank you for your feedback, and hope to see you out in the Fields of Justice, Summoner!
-Saint0fWar

+1
HOWEVER
i'd like to give some feedback.
1. you seem to find guardian angel very necessary. why is that?
2. I think it would be better to go full armor pen runes. it stacks well with his e.
3. I like your skill order, its what I prefer as well. but would there really be no situation where maxing w first would be viable?
4. I like your summoner spell choices. however perhaps give a section with other options?
5. give this build some more beef. it looks a little skinny.
that is all