Faceless Void is one of the hardest carry in this game. Here's the pros and cons for this guy!
This section is up to you!
Whenever I level up, here are somethings that I think about.
During early game, can the enemy harass you a lot? (if yes, get backtrack)
Are you the one being aggressive? (If yes, get time lock for the bash)
During mid game, the two skills that matters the most is time lock or time walk.
Choose one to level up, or both the spells are going to be mediocre.
I prefer Dire top or Radiant bot. Don't block the creeps until you at your tower. If you do block the creeps, then your tower might start attacking the enemy's creeps, pushing it their way.
Always start with culling blade and one tango.
Get a salve if you think your enemy is going to be bursty.
More tango if they harass you by poking you to death.
I always get boots first. Try getting it from the secret shop right next to you.
I do that so that I would be able to run away from my enemy.
Now, If you are winning your lane, get battle fury.
If you are just farming in your lane, get hand of midas.
If they are winning the lane, try switching lane, get bracer so you can survive, and build battle fury if you will be able to jungle, or hand of midas if you can get it before 15 minute. If you can't, build for battle fury.
Mask of Madness (MoM) is IMPORTANT on faceless void. Helps proc his passive, attack faster, lifesteal, and movement speed! If I get battle fury, I tend to get it after Claymore. Or I get it after Hand of Midas.
Then FINALLY power treads!!!
CRYSTALYS!!! CRITS! DAMAGE! CHEAP FOR ITS ABILITY!
Then I farm for butterfly for evasion and agility. Btw, EVASION STACKS WITH DODGE!!
Then, Daedalus for even more damage and crits!
Then, MKB for even MORE damage and bash.
The reason I build it like this is because when my team initiates, I want to be able to use my ult to stop everyone of their enemy, or at least the ones that can stun, and kill them before they can do anything. All this bash, attack speed, and the damage will be able to take out 1, 2, or 3 before they can do anything.
BKB. Do I need to explain? Even after chrono disappears, I can still lay havoc with this faceless void.
HOT. HP! To be a survivor!
Boots of travel can replace power treads after survival items for extra movement speed.
After getting boots of travel, I change MoM for Satanic for even more survival and more lifesteal. This is because I don't need more attack speed because of butterfly, and movement speed because of BoT.
Replace Hand of Midas with Mjollnr for way more attack speed, chain lightning, and damage. You don't need Hand of Midas' active anymore since you should be already farmed.
Divine Rapier. Get it to start raping the entire team.
Farm. He's a great last hitter because of base attack damage, and culling blade.
Get one time walk so that you can easily escape out of everything.
ALWAYS CARRY AROUND 1 OR 2 TP SCROLL. 135 gold is better then dying.
Also, you can use the TP scroll to tp into team fights and so on.
Look at your minimap. If you sense a team fight is about to happen, tp in. If someone is out of position, time walk in, chrono, and kill. If they initiate, do the same thing as before, but go for the carry or anyone that can stun.
Farm if not busy. But remember you are the carry. You carry your team to victory.