Hey everyone! I decided to make this build based on the fact that I have been seeing people play Diana a bit differently than I do, and I wanted to share my build. Please keep in mind that I only play against bots as I don't have much time to play PVP, but I would keep the same build just minus the Majei.

This guide is a work in progress, and I plan on making it as detailed as possible. So if you have any suggestions please let me know!

Now lets get to the build!

Pros:

Great burst damage
Has a shield
Low CD's
Great at farming

Cons:

Slow moving
Can be easy to kill early on

I decided to go with a basic set up for ability power runes. The runes themselves are pretty self explanatory. 9 marks of insight, 9 seals of potency, 9 glyphs of force, and 3 quints of potency. Feel free to change them up if you like but these runes give you plenty of AP to take on your foes.

Again, pretty straight forward here. I went with a basic AP set up for my masteries, except that I took two points in attack speed. This will benefit Diana greatly since every 3rd attack deals bonus magic damage. The faster you can get to that third attack the more damage you will be doing.

Now on to the items. Since I play against bots I always start with an amplifying tome so that I can get my Mejai's. If you are playing PVP and not bots, skip the Mejai and get yourself a Sheen. If you are dying a bunch during bots forget the Mejai as well. It's a pointless item if you can't keep the stacks. Usually I will port back the moment i hit 800 gold and buy the Mejai. If I am not paying attention, sometimes I will end up with enough to get my Mejai, as well as some form of boots. For your boots you want to go for mercury treads. 25 magic resist and tenacity is great for Diana. Especially since she is melee!

From here I get my hat as fast as possible. Generally you will get the rod first, but if you are doing great with farming go ahead for the whole hat. Feel free to farm up the creeps as much as you can or try and get yourself some stacks ;). Once you have your hat you should be able to land plenty of kills to get your Mejai up to 20 stacks. The next item to get is your Lich Bane. Diana is still way OP even after the nerf with a hat and Lich Bane.

Now that you are terrorizing the enemy get yourself an Unholy Grail. If the game is still going feel free to get an archangel staff for insane amounts of AP. Other options for your final item are a Hextech Gunblade or a Nashar's Tooth. Spell vamp is great from the gunblade, or you can get some ridiculous attack speed and AP from Nashar's Tooth. Either way you go you will be set.