Pros

- Decent range
- Decent burst
- Good CC
- Deals both magic damage and physical damage
- Fun to play!

Cons

- No escape
- Ulti is not a stun and its easy to avoid
- in a 1v1 situation he has no steroid since

Living Vengeance only affect you after you kill something

The supports i find works best with Varus is the ones with hard cc like Taric or Leona

Janna - I think she is just amazing together with Varus since she has good cc and can protect him from haras and also save you from very sticky situations.

Lux - even though i said hard cc works well with Varus i find Lux to be hard to play with as Varus i am not sure why though :/

Leona - she has so good cc when laning with Leona you just have to sit back and hit the champion she jumped on.

When you are laning as Varus you want to farm as much as possible. I would even go so far and say it's more important to farm than getting kills in lane. i usually aim for gettin aproximatly 90 cs every 10 min. you also dont wanna push the lane past half of the river since you are much more vonurble to ganks when you are pushed.
when herasing try to apply 3 stacks of Blighted Quiver and then hit them with your Piercing Arrow
Keep you'r wards up!!! if your support doesn't buy wards just buy some to prevent ganks (remember: buy a ward save a life)

If you are having a hard lane facing some champions with high burst such as Graves + Leona pick up one or two Doran's Blade to help you stay alive.

When fighting you number one priority should be staying at a safe distance and hitting something from the farthest range possible even if it is Malphite with Frozen Heart.
One big mistake many people do is that they think the adc has to jump in and focus the enemy adc. Take my tip when you play adc fokus is a lot of "nonsense". If you jump in to fokus the other adc that is standing behind his team, then you are dead. Dead = no damage

You also want to keep auto attacking since its your primary form of damage and when you have 3 stacks of Blighted Quiver shoot them with one of your abillities.

Piercing Arrow - You never want to charge it up in a figth since you cant autoattack when charging it just quickly press q when you have 3 stacks of Blighted Quiver on them. only charge it up on fleeing enemies and/or when you are herasing.

Blighted Quiver - Basicly attack enemies to get out as many stacks as possible ( Runaan's Hurricane is a great item to apply multiple stacks at once)

Hail of Arrows - Use it for chasing or escaping / triggering Blighted Quiver stacks (tip if you are dueling another adc shoot Hail of Arrows so they dont lifesteal as much as they should)

Chain of Corruption - You can use it to initiate a teamfight or hunting down running foe's (but saving it for a team fight is usualy better) use when enemies are grouped up.

Doran's Blade - Good early game item its cost effective and worth stacking one or two if you have problems in lane

Infinity Edge - It's the best damage output item in late game its a must have. I often get Infinity Edge right away after my Vampiric Scepter

Bloodthirster - Awesome sustain and gives much ad (I buy this first if the opponent got much haras and i have trouble staying in lane)

Blade of the Ruined King - Gives much damage if enemies has a lot of hp and gives you good sustain. Buy when enemies is stacking hp

Warmog's Armor - In late game you need some tankyness of a kind and warmogs gives you very much health to help you stay alive.

Guardian Angel - I actually prefer warmogs armor since a lot of time it feels like you are just waiting to die when they managed to pop the Guardian Angel passive + that it has a 5 min cooldown and the hp you get from warmogs doesn't. but its still a very good buy on Varus.

Frozen Mallet - Gives you amazing kiting abbility and also gives you good survivabilliy

Mercurial Scimitar - If you have problems with stron cc champs like Leona or enemy team has much magic damage this is a good item for you.

Last Whisper - The reason I didn't set this as a core item is that in solo q sometimes no one other than the main tank buys armor and sometimes he focuses more on mr than armor then you could buy this last. But acording to me its a must have item.

Phantom Dancer - wWrks great with Infinity Edge and gives you the attack speed you need and also gives you nice movement speed to improve chasing/running/positioning

Runaan's Hurricane - Works really good with Blade of the Ruined King since it applies on hit effects that includes you'r Blighted Quiver witch can give you tons of damage from just shooting a Piercing Arrow or Hail of Arrows on the enemy team

Varus is a pretty fast splitt pusher since his Piercing Arrow can almost kill an entire minion wave in one shot. Although if you are going to split push make sure you know where the enemies are and you have some wards.
If the enemies catch you when you gave pushed to far and you dont have you'r Chain of Corruption up
YOU WILL DIE!

This concludes my guide about Varus. It's my first guide and I hope it helped you. If you find somethign you think I should add leave a comment :D

Good luck in the fields of justice!