dota 2 guide

BIO
Just as higher states of energy seek a lower level, the Spectre known as Mercurial is a being of intense and violent energy who finds herself irresistibly drawn to scenes of strife as they unfold in the physical world. While her normal spectral state transcends sensory limitations, each time she takes on a physical manifestation, she is stricken by a loss of self--though not of purpose. In the clash of combat, her identity shatters and reconfigures, and she begins to regain awareness. She grasps that she is Mercurial the Spectre--and that all of her Haunts are but shadows of the one true Spectre. Focus comes in the struggle for survival; her true mind reasserts itself; until in the final moments of victory or defeat, she transcends matter and is restored once more to her eternal form.

INTRODUCTION
Spectre is an Agility Carry hero that will shine on late game. And on early-mid game, her job is to 24/7 farms. If you can't succeed farm, then you will be useless. So farm well cand carry your team into victory.
He is a hero that can teleport straight into enemy hero from anywhere on the map. And she also will deal damage to a lone hero and her damage is very painful on a lone hero.
She also deal damage to opponents using his health, which is the tankier she become, the more damage dealth on  a teamfight.

STATS

ABILITIES
1. Spectral Dagger
Spectre flings a dagger to draw a Shadow Path, dealing damage and slowing the movement speed of any enemies along the trail. Units hit by the dagger also trail a Shadow Path. While treading the path, Spectre phases through otherwise impassable terrain.
Mercurial's dagger eclipses the physical plane in shadow, a state in which mortals cower, but spectres thrive. 
This is your one and only: nuke. Send a path of shadow that deals some damage and slowing down the enemies. You can move without collision in the shadow path, you also can move through trees and high land.

2. Desolate
Deals bonus pure damage when Spectre attacks an enemy hero with no nearby allied units.
Often times, warriors find themselves alone with a vision of Mercurial - the fated question is if it is the true Spectre.
Attack with more damage to a lonely hero. So if you find a lonely hero in the jungle, don't afraid and fight one vs one. You will deal + 20 / 35 / 50 / 65 damage per attack based on this skill's level.
Combined with your ultimate, you can find a lonely hero with your ultimate which send a clone into every enemy hero, and then jump into that lonely hero and can harass him with extra damage.

3. Dispersion
Damage done to Spectre is reflected on her enemies, leaving her unharmed. The effect lessens with distance.
A daunting task lies before enemies of Mercurial - killing a shadow with blade and magic.
If your HP is being reduced, the HP loss percentage will damaging nearby enemies. It will become A very good skill the more HP you have because the damage received by your enemy will increase and become painful.
With the formula of this skill, you will deal more damage the more HP you have, so buying lots of Tarrasque will deal a massive AoE damage to nearby enemies. At least, if you have like 4000 HP and the enemy successfully kills you, they all will receive 4000x22%=880 damage

4. Haunt
Creates a spectral nemesis to attack each enemy hero after a short delay. Haunts are uncontrollable, take extra damage, and deal less damage than Spectre herself. At any moment during the duration, Spectre can use Reality to take the place of a given illusion.
At the height of combat, Mercurial's physical manifestation shatters, and the shadowy pieces haunt those who still cling to life.
Creates illusion of you that attack every enemy hero on the map. You can quickly jump into that illusion and your real self become the attacker of the enemy hero. If your real self has jumped, the other illusion will gone.

5. Reality

Spectre physically possesses a chosen Haunt, giving it solid reality while the other images blink out of existence.
The scattered shadows unite into the one true Spectre.
Jump into one of your illusions. And you can attack the enemy there. If you choose the lonely hero you can have additional damage from your 2nd skill Desolate.

SKILLBUILD
Level 1: Spectral Dagger
Level 2: Dispersion
Level 3: Spectral Dagger
Level 4: Desolate
Level 5: Spectral Dagger
Level 6: Haunt
Level 7: Spectral Dagger
Level 8: Desolate
Level 9 : Desolate
Level 10: Desolate
Level 11: Haunt
Level 12: Dispersion
Level 13: Dispersion
Level 14: Dispersion
Level 15: Stats
Level 16: Haunt
Level 17-25: Stats

Why take Spectral Dagger for level 1? You need Spectral Dagger to escape if enemy wants to get firstblood by killing you so you can use Spectral Dagger into trees or hill and escape there.

Why maxed Spectral Dagger first?  This is your only nuke, you will need this for ganking, farming, killing, and also escaping for early mid game.

Why maxed Desolate before Dispersion? Desolate is needed for mid game ganking which needs enemy to be alone to deal the additional damage, and if you increase this too late, the enemy is rarely to be alone because on late game, a team should be almost always together. So on about 15-30 minute into the game, is about the right time to increase this skill.
And Dispersion will deal more damage the more HP you have, and the late game is the time your HP reaches it's maximum.