Viegar is one of my strongest heros, and I believe one of the strongest in the game. Many will argue this but a well played veig is nearly impossible to beat 1v1 without the right summoner skills (this is if all things are equal) ie, your opponent doesnt have 5 or more kills vrs u..lol
Vrs ranged heros the key is to teach them the meaning of pain! And that u are evil..lol ok enough of the vaugeness.
If u are going mid without 2health pots and a crystal u are going to have a tough time with harrass, also having clarity will help u avoid harrass. Now im sure people are like "wtf this guy cant be serious". But I am a really good veig and ive never finished a game where I didnt do my part as veig.
U got a few options they may sound crazy but they work.
1: have your team help u get the blue buff at lvl 1. This is pretty tough to do and probably the worst option.
2: buy boots and pots as your first items. This will give u more manuverability and help u go in for quick snipes with your q. Again, not the best option but the added speed is useful.
3. This will sound crazy. Dont get q first get your dark matter. if u last hit like a champ with lvl1 q it is about 5 last hits before u hit lvl 2. So basicaly u are losing 5ap getting q second. most players will not land that many last hits anyways befor lvl 2 unless they are decent. Your not really giving up much. If u lvl darkmatter first it will only take landing a few on an opponent befor they start to get scared. Also you can use it to last hit and also weaken the entire creepwave, u want to prevent the wave from getting to your tower because the tower will take your lasthits and some dmg. The key to landing darkmatter vrs more aggressive opponents is to watch your creepwave hp. Try pretending u are trying to lasthit your own creep which they are also trying to last hit. The only difference is, u are casting darkmatter on them not targeting your creep. The reason for this is, if they try to attack at the same time u cast matter,they cannot avoid it once thier attack animation starts. Later in the game they can but unless they stacked attack speed runes they cant dodge darkmatter if u cast it on them when they enter thier attack animation. Also, if u miss your matters, u make matters worse... Now they see u suck and even worse, u got no mana left because matters so expensive. The way I see it is, u can burn mana and do some dmg to them, maybe getting some last hits in or, u can sit back with tons of mana, nohp cuz they potot your little blue face and now u got nothing for it.
the second way to land matter without horizon, and also a realy great way to screw with your opponents head is to hit "s" and just stand behind your creep wall. Withdarkmatter qued so that its furthest range is right on the edge of them while they face u. "hmmm" they think..."this guys a total noob just standing thier like a little smurf", then as soon as they take a step toward u you cast. Most of the time they stepped dead in the center of you aoe and withou boots they arent going to make it out. Do that a couple times and they wont be so quick to step at you.
4: feed and qq then leave because you are playing a char that is too hard for you unless you are playing vrs a melee hero...lol
This all being said, you are going to take hits as viegar. You need health pots or.. You take mana pots and plan on spamming matter. I prefer clarity as a summoner skill because the early mana helps you combo better and late game you dont really need summoner skills to get kills. learn to land matter based on reaction to your opponent not just with horizon or exauhst. I know it is not optimal to get q at lvl 2 but if you have harrass issues it is very strong. A viegar that can land matter without a stun scares the poo out of people. Maybe not the first one u land but about the 3rd time u spray your goo in thier face they wont bother u again. This is until they think they can step to you and you burst magic all over them either killing them or making them run like a little girl...