That's my support guide for Diana. You will find here ways to build this champion as Fighter/Assassin on Top lane or Assassin/Fighter ap on mid lane.

Pros:

• High defense in both builds
• High magic damage in both builds
• Good CC on Top build

Cons:

• Slow early game
• Hard to stay fine until level 6
• High mana usage

Flash : obviously flash on Diana would help in anything, even strategically. Nice escape if you combine it with Diana's ultimate Lunar Rush


Ignite : use it if someone already picked Teleport in some lane (except if it was the support).


Teleport : standard top laner summoner spell, the best one in my opinion to any tanky top laner, it allows you to support in any lane when you use it wisely, as Diana after build Lich Bane start to have more movement speed, it will allow even better to you to help other lanes as well.

Mark : better put Greater Mark of Magic Penetration or Hybrid Penetration, better use the Hybrid one, as Diana is basically focused on basic attack's third hit after the combos.

Seals : greater seals of armor and mana regen will help the hell out of Diana since on it early game, you will have a lot of mana usage and less defensive stuff instead, as armor and magic resist. In this case buy Crystalline Flask to help your mana regen.

Glyphs :greater glyphs of magic resist will defend you against Ap Mids you get, assassin's or not, or ranged, whatever. It will better you have early game Magic Resist instead Scaling magic resist.

Quintessences : Ability power ones, no problem.

Mark : better put Greater Mark of Magic Penetration or Hybrid Penetration, better use the Hybrid one, as Diana is basically focused on basic attack's third hit after the combos.

Seals : greater seals of armor so you will later only need to get only an armor item on the start, like Glacial Shroud to Frozen Heart after some ability power items.

Glyphs :greater glyphs of scaling magic resist if you don't get an fighter/assassin AP on top, what is kinda rare to find, you normally see AD Nidalee's on top lane, for example. So the scaling would be hell better for Diana, except if you got a Rumble on top, or Gragas [...]

Quintessences : Ability power ones.

AP carry masteries on it, as 21/9 for example.

Doran's Ring : normal offensive starting option, you can get this one for more health, AP and mana regen.


Health Potion : normally starts with x2 Health Potions in any of the situations, except if you start with Cloth Armor, you will get x5 Health Potions and with Boots with x4 Health Potions.


Crystalline Flask : starts if you see that you will use too much mana, as against an poking champion as Ryze and such.

Haunting Guise : Your core item for magic penetration, build it first after the Sorcerer's Shoes.

Sorcerer's Shoes : Another item of magic penetration, your next ability power items will give a lot more damage now as you have +30 of magic pen. on these items.

Sheen : this item you can built in three different items, both three: Trinity Force, Lich Bane and Iceborn Gauntlet works on Diana, either TOP or MID.

Glacial Shroud (TOP) : build it on start against fighter/assassin ADs on TOP Lane.

Sorcerer's Shoes : your magic penetration item, buy it first after your initial items.

Liandry's Torment : another magic pen item, work really good as offensive item, you don't need to rush it after do Haunting Guise, build it after Nashor's Tooth. Gives you health either.

Lich Bane : to gives you mana, the Spellblade passive, AP and movement speed, really good item for an ap assassin.

Nashor's Tooth : gives you %20 Cooldown Reduction and attack speed with ability power.

Banshee's Veil : your defensive item, you can replace it for another one if you don't have any ap on the enemy team. As Guardian Angel or Frozen Heart. Gives you magic resistance and health.

Rabadon's Deathcap : gives you pure ap and plus increases your ap +30%

Sorcerer's Shoes : your magic penetration item, buy it first after your initial items.

Liandry's Torment : another magic pen item, work really good as offensive item, you don't need to rush it after do Haunting Guise, build it after Nashor's Tooth. Gives you health either.

Lich Bane : to gives you mana, the Spellblade passive, AP and movement speed, really good item for an ap assassin.

Randuin's Omen : one of your tanky items. Gives you health and armor, plus give you cc.

Nashor's Tooth : Giving you %20 cooldown reduction, increases your attack speed and ability power.

Banshee's Veil : Another tanky item, giving you magic resistance instead.

Nice Crowd control using the Randuin's Omen and the Moonfall. Try to hit the most enemies you can with your Crescent Strike so you can use the Lunar Rush with no cooldown reduction cost.

Use your Lunar Rush without using Crescent Strike before in killing cases, escapes or initiations.

With both builds you have an high chance to get tanky easily. Go for it with this build!

I may start posting builds here that I don't post in my blog called All LoL Builds, hope you enjoy this and the other ones i will post here! ^^