Faceless Void has come back into meta as a potential offlaner. While he is a more greedy pick he definitely can be extremely strong under the right conditions.
Treads - No surprises here. Personally i leave these on strength except when int switching for time walk, or when i solo chrono someone and theres no other heroes around.
Helm of the Dominator - This item is the only reason why offlane void is good. Seige creeps spawn at 5 mins and 10 mins. Aim to complete treads and HotD by 10 mins too get a double siege creep wave. I could write a whole guide on this item, but i will give a breif comment on preferable creeps. Seige creeps are A priority untill around 30 mins. Other good early creeps are Satyr Tormentors(HP regen and a good Nuke), Hellbear Smasher (nuke and attack speed), Centaur (Stun), Dark Troll Summoner (net for skill shot set up eg. hook,SS, mirana arrow, and summons creeps). As for later in the game the best creep is an Alpha wolf(Bonus Damage) with the potential for Kobold Foreman(Movespeed), both of these creeps i set to follow my carry or mid laner.
Shadow Blade - Normally i avoid this item but its way too good on void. its gives you alot of damage, makes your initiations very reliable, allows you to split push a little easier and allows you to solo kill most supports without chrono.
Aghanims Scepter - Great stats, it means you can throw chrono's left and right with a low risk of the enemy capitalising on the down time.
Black King Bar - You will need to buy this before Aghs some games. This item is extremely good on void.
Time Walk - Very strong ablity, this is the ability that allows you to offlane and initaite, make sure you get value from it buy trading for the full 2 seconds or baiting a nuke before using the skill.
Time Dilation - 1 point in this will allow you to fight without chrono sommewhat. It also lets you solo some supports with your SB. walk up and hit the sup, get stunned time walk, dilate and beat their heads in.
Time lock - Everybody loves permabash. On a safelane build this would be maxed first however you will be utilising a more aggressive play style and also not buying MoM so it is maxed second.
Chronoshpere - What an ability! A 5 second Aoe disable with a long cooldown. Use this as much as possible sub 20 mins. Solo chronoing an enemy core is perfectly fine if you get the kill. Keep track of kill streaks if you can and check enemy levels on the scoreboard so that you can get the most value for the chrono. Later in the game use this on their most impactful heroes or someone you must lock down eg. riki, disrupter, sniper, puck.
I first pick Void. The other team will expect you to go safelane. Which leaves your team to get a preferable match up. Defensive supports are pretty garbage in pubs and it'll make your offlane way easier if they pick one so i would worry about that too much.
If you get Trilaned, you are going to need a support to help you most likely. If you get to play 1 v 1 against their carry you should win that lane in most match-ups or at least trade farm. If you think your getting Trilaned and you wont be getting help try for the offlane pull, even if you have to die for it it is worth it. I would also recommend blocking the pull camp with a sentry.
Once you get Chrono and HotD call your supports maybe even your carry, chrono the carrry solo if you have too and take their tier 1. Now switch lanes with your carry and repeat the process of Chronoshpering and pushing. Make sure to ask your supports to ward the enemy jungle for your carry. This is extremely important, it will secure half a map of farm for your carry and cripple the enemies resources.
Keep the lanes pushed out as much as possible, time walk into the trees with a TP is very hard to pin down. you can even use satyr tormentors to nuke creep waves if the other team is pressuring you hard.
As it gets later into the game just make sure to play around your team. Smoking as 5 and immediately going objectives because you pushed out the lanes will win you most games.
Prioritise making space for your other cores, this will sometimes mean ignoring team fights, sounds weird but solo chronoing and killing an enemy core and picking up a lane of towers is very possible with this hero. Running down lanes just to force rotations is what dota is about and this hero excells at it. Vision is more important then ever so buy the damn wards if you have too. Put them as deep as possible and run down those lanes.
Good luck and i wish you all the best on the grind.
As always any questions or criticisms are welcome and if you like the guide please up vote. I will also endever to put this guide on steam so poeple can use it in game.