Introduction
Mirana is, without a doubt, one of the most balanced heroes on the game. She has an AoE nuke that, if used in close range, deals a good amount of damage; one of the best single targeted stuns, an amazing fleeing or pursuing skill, and a global invisibility, which can be used for various purposes. She has the ability, if played in the right hands, to own early , mid and late game. She is also a very versatile hero: she can be a amazing ganker, a strong semi-carry and a ok support hero.
She is also a hero that requires a lot of practice, unlike other click-and-kill heroes, you will need to play a good amount of games before getting a good average of hits with Elune's Arrow.

Description
A matriarch and high priestess of Elune's blessed order, Mirana Nightshade serves as a light in darkness for the front line of the Sentinel ranks, raining arrows and falling stars alike upon the shambling undead masses of the Undead Scourge, while her very presence is said to be so holy that it melts away the fatigue of nearby allies, giving them greater haste on the battlefield. In times of need however, she can fade herself and others around her into the safety of invisibility, making her a potent supporter matched by few.

Pros and Cons
Pros
- Can own early, mid and late game
- Excellent escape mechanisms
- Ultimate is helpful for the whole team
- Excellent ganker early-mid game
- Can play the role of a support or a semi-carry hero late game.
Cons
- Requires a lot of practice to master Elune's Arrow.
- Somewhat fragile.
- Somewhat item dependent late game.

Mirana: Semi-carry or support?
An important decision to make at mid-game is if you're going to play a support or a semi-ganker PotM. In my opinion, the semi-carrier is a better use for Mirana, but sometimes, it's worth it to go Support. So, what do you need to check to make this decision? Basically you need to look your allies, especially in pubs, where everyone -random or simply pick without caring for what the team has. Sometimes you will find yourself with a extremely late-game team. Your team already has a Troll and a Mortred so in this case go for support. Sometimes the opposite will happen: there are no carriers, Mirana then is supposed to carry late game.

Skill Build
1 - Elune's Arrow 1 / Leap 1
2 - Leap 1 / Elune's Arrow 1
3 - Starfall 1
4 - Starfall 2
5 - Starfall 3
6 - Elune's Arrow 2
7 - Starfall 4
8 - Elune's Arrow 3
9 - Elune's Arrow 4
10 - Moonlight Shadow 1
11 - Moonlight Shadow 2
12 - Leap 2
13 - Leap 3
14 - Leap 4
15 - Stats
16 - Moonlight Shadow 3
17 - Stats
18 - Stats
19 - Stats
20 - Stats
21 - Stats
22 - Stats
23 - Stats
24 - Stats
25 - Stats

Skill Build Justification
Elune’s Arrow and Leap for the first two levels. The choice of which one to go for first is entirely yours. You should get Elune’s Arrow if you think your team will try an early gank or Leap if you’re trying to escape an early gank attempt. I usually go with Elune’s Arrow but hey, it’s your choice.
Next you want to maximize Starfall. The reason why you want to maximize Starfall before Elune’s Arrow, is because Starfall is a much more reliable skill then Elune’s Arrow. You can’t really miss Starfall. Besides Elune’s Arrow’s stun stays the same at all levels, so level 1 is fine for you.
At level 9 you should've maxed out both Starfall and Elune’s Arrow, because, as the game goes on, the less effective your nuke's damage is.
Next two points at your ultimate, you don't want your ultimate earlier because you won't really have the mana required to use it, since you'll be ganking all the time.
Following then max out Leap. If you feel you need it, you can trade Leap for Stats, although I really think Leap is superior.
Same thing for your ultimate, if you feel you need the extra stats go ahead and take them instead of Moonlight Shadow.

How to play
Early Game
The game begins and you picked/randomed PotM. First thing is choosing your lane. Mirana is a pretty good solo hero, but if there are any better heroes for the job (Tinker, Shadow fiend), you should leave the solo lane for them. Try harassing your enemies with normal attacks on the first few levels. At level three you are already able of killing someone. If the opportunity appears throw and arrow, and try killing them. The best time to do this is when your creeps just ended killing their creeps. If you're laned with a disabler wait for him to stun first, so you have 100% chance of hitting with your arrow. This, of course, will require some communication. Try last-hitting and denying until level 6-7. Until then you should have at least your Wand and Boots or Bottle. Your choice, I usually go with Bottle first, since you have leap you can keep up to your enemies but hey, your choice. At this point you should look for good ganking opportunities without wasting too much time without farming. Mirana is somewhat item-dependent late-game so try roaming as shortly as possible. But don't just stay AFK-farming either, as the game goes one your 2 damage skills lose their effectiveness.

Middle Game
Almost the same as Early Game, try keep a balance between farming and ganking. If you see some allies are getting ganked don't hesitate on using Moonlight Shadow. Somewhere in this stage you should complete or almost complete your core. At this point, you can use use Starfall from times to times to farm and push.

Late Game
At this point of the game you should simply accompany your team in pushes or team battles. Use Moonlight Shadow for positioning or fleeing. Try keeping some distance and not getting to much attention. If your team is winning and you see some fleeing enemies, feel free to leap in and snatch a kill. Spam Starfall to farm and push, but in a much intensive way then in middle game. Especially if you went for a support build and now have lots of mana and mana regen.