Please remember...
This guide is still being edited but is almost done. The only thing missing is the explanation for the Situational Items list. Other than that, the item should be 100% and I hope you all enjoy it :)
~Enaio~
Thank you for viewing this guide (PLEASE READ BEFORE CONTINUING)
I would like to thank you for taking your time to look at this guide. I hope you enjoy how I build 
Diana and I hope it helps you as much as possible (whether that is improving your gameplay as Diana or looking for a way to counter the Champion).
Please comment if you have any questions. Although, I do ask you to wait on voting after your comment so that if you have any questions after reading the whole guide, I can answer them with a more in-depth explanation in the comments (As I have done already).
(I have put this thank you up here not only because I do want to thank you for your time, but also because people have ignored the thank you below the chapters of the actual guide and have not given me a chance to explain myself on this guide. Please have the respect to let me answer questions you may have before voting the guide down or up.)
Items that I would not build that I have seen in other guides
Even though I have created my own guide and do a lot of testing, I do read up on what other players think suits this champion. There are a few items that I have already put into the items list that are on those guides but this is a list of items I have seen on other guides, have tested, and I am fully against building these items for this build.
1. 
Guardian Angel - This item is a very useful item, but as Diana, I see it as a downfall. Why? First, it only gives you 750 health and 250 mana after you resurrect. If you are being targeted at all, this item will not give you enough time to get your targets down. You may be able to get away by using 
Flash or your Q/R combo on a near by minion group but that is very unlikely if you are being targeted. Also, even though this gives you a decent amount of Magic Resist and Armor, your job with this build is not to be tank or survive team fights, its to get in, kill your target, and repeat if you have succeeded the first attempt.
2. 
Rod of Ages - This item is kind of a tricky thing to place in this build, or even on this character. It only gives you 80 AP and 'some' Health and Mana. As an assassin champion, your job is not to think about surviving a team fight, its about getting as much damage out as possible and not letting your target get away from you.
3/4. 
Nashor's Tooth and 
Malady - I do state that I use Berserker's Greaves and Alacrity runes to give me attack speed to get through the jungle, but I do not depend on them to get ganks/kills. My main focus with this build is to put out as much damage as I possible can, in as little time as possible. Banking on my passive does not give me that quickness I need to get in and get out, even if I get my attack speed up to 2.5, it's still not as fast as getting items that cut down the enemy's Magic Resist or slowing them so that I can get that extra hit from my shield's orbs or my 2nd Q/R combo if the first one does not take them down.
Thank you for the people that have suggested these items to me, I think that they are good items for Diana, but not for this build. This build is meant to be a 'get in/kill and if possible get out' build.
Jungling
Unlike my original guide, I am not gonna use paint to show the path. It is way too ****py looking. So instead, I figured I would just cut out the monsters pictures to show the path in the explanation. Hope this works the way I want it to and I hope you all like it.
First - Wolves
You, without any team help, can easily take down Wolves before Blue Golem spawns. To do this, stand in front of the Wolves spawn point and when they spawn, start attacking while at the same time activating 
Pale Cascade. This will allow your first shield to be almost fully used before each orb hits the Wolves and refreshing the shield.
Second - Ancient Golem
You are able to do this without a leash, but a leash would not hurt if provided. Be sure to group up the minions so that you can utilize the orbs from your shield. Again, make sure to get full length of the first shield, so do not stand directly on top of the minions. You should be able to activate your shield twice before taking down the Ancient Golem. Once the Ancient Golem is low enough, 
Smite for the extra Gold.
Third - Wraiths
When you are right in front of the bush next to wraiths, use 
Crescent Strike to hit them and pull them toward the bush. Be sure not to stand in the bush because the minions will reset if you are in the bush to far away. Once they start hitting you, activate Pale Cascade and utilize the first and second shield.
Fourth - Ancient Lizard
Use your Crescent Strike to pull them into the bushes next to the spawn point. Always do this because if you are facing another team that has the ability to counter jungle, you will be able to see it coming before they see you in the bush. Also, this allows you to group up the minions in front of you so you can utilize the orbs from Pale Cascade. Once, the Ancient Lizard is low enough, Smite for the extra gold.
UPDATE: I have had several occasions where my Smite is not up by the time I am at Ancient Lizard and does not come up by the time I am able to kill it. Personally, I have used it to kill Wraiths and it is normally up by the time I need it for Ancient Golem.
Options:
Option 1 - 2nd Wraiths
Right after you take Red, Wraiths should be up again. You can easily take them down the same way as before. It is possible for this to be down after you take Red Buff. If so, just harass the mid lane a little bit with Crescent Strike while waiting for them to respawn.
Option 2 - Gank
This is the preferable option. If you see a lane to far pushed, I would attempt to gank (ONLY if its mid or bottom, top is too far away for this and the situation could change right before you get up there, so do not risk the time travel up there on the first clear.)
This option only pertains to taking down Ancient Lizard the FIRST time. If you have taken Ancient Lizard a second time (or any number of times after the first), and top needs you to gank or your help, you should always run up there. This was a misunderstanding that a friend pointed out and I wanted to make sure no one else got the impression that I did not think you should gank top at all.
Option 3 - 2nd Wolves
Sometimes, you can go through the jungle and Wraiths will not be up after Red. If this happens, I suggest running over to Wolves and getting a little bit more Exp while waiting for Wraiths to spawn.
Ganking
Before level 6:
It is possible to gank before level 6. You should be able to at least get one gank off utilizing your Flash and 
Moonfall. There are two situations a lane can be in, pushed in or dead even (I would not suggest ganking underneath a tower before level 6, its possible but risky).
Push in:
If your teammate(s) is/are pushed to their turrets, you can use Crescent Strike to get starting damage on the target you are going for. Always Crescent Strike from a bush or right after you come out of the bush, the travel speed of Crescent Strike is not that fast and easily dodged if you give them too much of a heads up that you are ganking the lane. Once it hits, put Pale Cascade up for sustain. If they are close enough, you do not need to use Flash, just use Moonfall and get the damage on them from Pale Cascade to activate your second shield, but if they are too far and you believe you can at least kill one of them, Flash to the closest target, use Moonfall and get the kill. Crescent Strike should be up if you see them running away with low health, just aim ahead of the target.
Dead even:
This is the tougher of the two situations. Personally, I have tried the same strategy as if they were pushing the tower but I have lost a kill or two that way and suggest to do it this way. Activate Pale Cascade for sustain and Flash in. While they are running away or even targeting you, use Moonfall and CC them and than finish them off with Crescent Strike. If you are being counter ganked at this time, your W should be up and just walk away.
Ganking after Level 6:
After you are level 6, you want to use your Q/R combination as much as possible to gank. The combination will easily get you to the target. After the combo, activate your W for sustain. If the target is running away, you have a few options:
Option 1 - Use your E
Only use this option if they are close enough. If they are, hit your E and than hit them with Crescent Strike and 
Lunar Rush again. This should give you enough damage to get the kill.
Option 2 - Use your Ult
This is only if you absolutely know you can kill them. If you believe you can take them down, Lunar Rush in and hit them with Crescent Strike immediately after. Then activate Pale Cascade and Moonfall to get extra damage if need be and than either run out with your shield up or Flash away if you are under the tower or in danger of being killed yourself.
I will put videos up in the future. Unfortunately, I have not been able to video tape any game play.
Being countered?
There are several items that can counter you:
1. 
Banshee's Veil - This item can ruin your Q/R combo. It completely negates the damage and moonlight debuff from Crescent Strike so if you are ganking someone with this time, be sure that the person in lane already has removed the Banshee's Veil buff. There is no real counter to this.
2. 
Zhonya's Hourglass - This item's active can ruin your Q/R combo and Moonfall. If you are ganking/attacking someone with this item, be sure to watch for this active. There is no real counter to this item.
3. 
Quicksilver Sash/
Mercurial Scimitar - This can take your debuff off your target which can put Lunar Rush on cooldown.
If I do find any counters to these items I will update as soon as possible.
Other items that aren't a full on counter but can really screw you up:
1. 
Frozen Heart - Slows your attack speed. If you are facing someone with this item, only use Abilities.
2. 
Randuin's Omen - Slows your attack speed on hit and has an active to slow your movement speed and attack speed. If you are facing someone with this item, same as Frozen Heart, use your Abilities to get the most damage possible. If the enemy team is going to jump on you, you have two options:
- Find the furthest target, use your Q/R combo to get out, than Flash away.
- Flash away.
Other than that, there is really nothing you can do.
3. 
Hextech Gunblade - The active on this can keep you from getting away in team fights. If an enemy has used this item on you, you have the same two options that you have with Randuin's Omen.
There are more items that can really mess up your ganking abilities and team fight abilities but those are the main ones to watch out for.
Thank you for reading!!!
I hope this build has helped you with jungling Diana or even countering Diana.
If you have any questions or suggestions, please post a comment. Please DO NOT vote until all your questions are answered and you have no doubt in your mind how you want to vote.
Again thanks for reading and good luck on the battle field.
Current Results
I will be putting more results from Season 3 in the future. Been rather busy.
Where'd the mid guide go?
Unfortunately, I have taken it off the guide for now. I will add it back to the guide when I can make it but until than I am keeping it off.
Build Guide
Discussion (23)
Greater Mark of Magic Penetration x 9
Greater Seal of Armor x 9
Cloth Armor, which most junglers do. This gives her some early resistance against enemy champions along with resistance against the minions.
Greater Glyph of Ability Power x 9
Greater Quintessence of Ability Power x 3
Summoner's Resolve
for the extra 10 gold by using 
Hardiness
or
Resistance
but now that it is on the 2nd tier of defensive masteries, I would suggest going with
Durability
and getting
Veteran's Scars
for the extra health going through the jungle, since that has also been improved. And instead of getting
Tough Skin
and
Bladed Armor
to help with the improved jungle minions.
Amplifying Tome but you wont have the Health Pots to give you the health to get through the jungle without help from your team.
Liandry's Torment - More Magic Pen to cut down enemy champions. Also, has an amazing passive that puts a DoT on the enemy (almost like Ignite but with magic damage instead of true damage). Don't forget it gives you a good amount of AP.
Abyssal Scepter - Lowers the enemy team's total Magic Resistance and gives you a great amount of AP. Gives you enough Magic Resistance to get in and do your damage and possibly get out and repeat the process.
Spirit of the Spectral Wraith - This helps with regaining health in the jungle after a fight and also helps you survive while you are putting out your damage in team fights. The cooldown reduction is helpful as well so you can spam your Q/R a lot more.
Lich Bane - The damage from Spellblade is too good to not make this a core item on her. Also the extra AP and Mana is great.
Rabadon's Deathcap - It's a 'must build item' on every AP champion that is focusing on putting out damage.
Iceborn Gauntlet in this build but didn't even mean to put it in at all, not even a situational item on her. If you voted the guide down for this, again the guide is in construction right now and I have not finished it. Almost there though!
