Diana Jungle is a favorite of mine and I have been spamming it lately. She is quite strong at the moment due to the recent changes to the AP jungle item. She is a unique champion in that she is a melee AP champion which means she has a couple of unique builds and items she excels with. Her early clear is actually quite strong as she is one of the only junglers I have found lately that can do a full clear without backing for items. This is nice because it makes a fast lv 6 happen. She isn't useful pre 6, but when she hits 6 her powerpike is very strong. You might have noticed that in my masteries page I went with the CDR instead of the atk speed option. I feel that CDR is better early game for jungler clears to help keep that W sheild up more often. I think too the 5% CDR is more noticeable than 5% atk speed would be. The runglaive has a bit of CDR and so does the Nashor's Tooth, so all told you end up with a healthy 35% all together and you cap it when you have the blue buff (which should be as often as possible). For the jungle I like to prioritize CDR more for the early game, but because Diana is reliant on spells for the bulk of her damage it is useful all through the game too. As my rule I love on hit effects like the sheen and Luden's Echo. Depending on the situation and matchup, there is plenty of wiggle room in the build to match the game you're in as well.

Excellent duelist
Strong split pusher
very hard to manage is she snowballs
Very noticeable lv 6 power spike
Strong jungle clears
low/ medium skill cap

Weak pre 6
Ganks reliant on chaining combos
Small mana pool
Fairly squishy with most builds
Small attack range means she gets pushed around in some matchups

Diana has a very good passive for the jungle: every third auto attack you will cleave in an area of effect for bonus damage. (This is why I like to get as much attack speed as I can to proc it as often as possible.) Your Q is a unique skill shot, in that it doesn't go in a straight line but rather in a cressant to the target. (this means it can go around things like Yasuo' wind wall and Braum's Shield.) It marks all of the enemy units it strikes with a moonlight debuff for a few seconds. your W is what makes your clears so good, it is a shield when activated and three little orbs pop up around you, When the orbs strike an enemy unit they detonate dealing damage. If all three detonate in a short period of time than you get a bonus shield for a few seconds. Your E is not all that useful in the jungle except that it will CC the scuttle crab which permanently takes armour and magic resist from it. it draws all enemy units in a short area into you and CC's then briefly. It is expensive and has a long cooldown. Finally, your R is the lunar rush, You dash to an enemy within range and deal a good chunk of damage to them. This is where the combo I will cover later comes into play. If a target has the moonlight debuff on them, than you can jump to them and you get an instant reset on your ulti. So it effectively has two charges on it when used properly.

I always start my Gromp, a leash is very nice as it saves resources. (You want to make sure that you get all the XP though as losing some to the leasher will mean you don't hit Lv 2 after the camp. I also tend to smite the gromp.) Than I go do my blue, (I find I need to use my first potion during this camp.) After the blue you have increased cooldown reduction as well as mana regen which you very much need in your kit. I do the wolves, and go straight to my red. I smite the red and then go to the raptors. I finish my clear by killing the krugs and checking the upper river scuttle crab. If it is up, I take it and back with around 900 gold. Diana doesn't have very strong ganks, and pre 6 they are more about relieving some lane pressure than actually getting kills. Once you hit 6 though you have some kill pressure if you work with the laners properly.

Diana is very good at bursting squishies and in lengthy fights is useful also because it allows you to get multiple Q's off for the auto reset on your ultimate. Your main role is to gank when you can and scale into the mid/late game when you can be very effective. The runeglaive enchantment makes this power spike happen somewhat sooner, but it still takes a couple items before you really become a power carry. If you get ahead in the early game than you can carry by roaming around and making picks and then going for objectives like dragon, baron, or turrets afterwards. If you find yourself behind, than you should build into a more utility role with some armour and depending on your team comp (whether you have a tank or two) you can either group up and jump on the squishies in the back line, or go split push them to death. The combo is not all that hard to use, but it is reliant on your ability to connect your Q to the target you want to jump on. The combo I use when ganking and dueling is to throw my Q at them and when it hits I immediately jump to them with R. As soon as I hit them, I pop my W shield and let it get the full charge off. By this point the burst is too much for the enemy and they will likely either flash away (which is worth) or try to turn and run. I always end my combo with E to pull them back to me and let me either get a few autos off or use the second charge on my ulti to finish them off.

Once you find yourself super fed, you have an easy route to the end of the game, provided you're lanes didn't get stomped. (If your lanes got stomped, than you didn't do your job as a jungler to help your laners) The best way I find is to go through the enemy jungle and place a few wards and get a few picks. Your transition these picks into objectives like turrets and barons. Eventually you will break the enemy's back in either a teamfight or through a split push with other teammates depending on your team comp. You are able to 1 V 1 anyone and in some cases even 2 V 1. The sweeper and upgraded Oracles lense trinkets are excellent buys because you can deny the enemy's vision which helps with the making picks part of the plan. pink wards are also very important for this. They give both vision and vision denial. Chilling smite is also a good buy because it slows enemies making it so they can't run away.

If it happens that you are behind in the game and having a tough time, than fear not. You will have to alter your build a bit, but you can get back in the game without too much trouble most times. I find it helps to play more passive and get more wards on the map to get more information for your team. I build some armor or MR and probably have to group up and teamfight. Eventually you will scale to the point that you are able to duel anyone and then you can splitpush. Play safe and don't go into a fight with low mana (you will either die or be forced to blow a summoner which is almost always flash). Rod of Ages is a good choice if you get behind early because it gives both mana and health so you get fairly tanky off of it. I like challenging smite for these situations because it makes dueling much easier for you with the reduced damage as well as the true damage you do to the enemy.

Diana Jungle is quite strong at the moment and it seems to me at least for now, people don't really know how to play against it. She is good at bursting as well as more sustained fights as long as she doesn't get bursted out herself. I tend to play her fairly passively until I hit 6 and then I play very aggressively to try and snowball my laners. She has a few poor matchups, basically anyone who could potentially invade you early. But she scales well and she is prone to take over the game at a moment's notice. Your W lets you win almost any trade and your ulti has a reset on it and even if you cant get it, it's on a very low cooldown (23 seconds I think at level 6). I play Diana jungle a lot as well as mid lane Diana at times too. I hope you found this guide useful and let me know if you have any questions, complaints, or corrections for me.