Have you ever wanted to ks a kill from your ally while their target is at or near full health? Well, I guess you did because you are reading my guide, and you are playing the master of Kill-Stealing himself: Veigar, the Tiny Master of Evil. Without a doubt, Veigar can get the most Ap out of any Champion in the game. He has an ability that turns him into a built in Mejai's Soulstealer without an upper limit, and he doesn't lose stacks when he dies, and best of all, it is free, and you have it from level 1.

Note: This guide is a different style and mentality than all of my other guides, (being that the point is kill stealing from your team so that you can become ridiculously powerful.) But in the end you are still in it to win it, so don't screw your team over just so you can 1 shot their AD carry (because you CAN).

This is a comic guide, but other than the kill-stealing aspect, this build is EXTREMELY viable and effective.

Now on to the Fun part: the Kill-Stealing!

Early Game / The buildup

Because you are more important than anyone else on your team, you get mid. If you have a Karthus who wants his ult early, he can just make like a Calzone and stuff it, cuz mid is yours!
So, once you have established your supposed superiority over the rest of your team, head mid. Now, because you refuse to do anything but KS, you are not even going to attack the other mid champ until you can 3 shot him. (usually around level 11). (I am not kidding, if you do it this way, the other guy will eventually over extend and you will quickly destroy him, no matter who he is.)

Your goal is to kill pretty much everything with your Baleful Strike. You will NOT use Dark Matter on creeps, (or heroes except when going for the kill). Your Event Horizon is pretty much for defensive use whenever the other guy decides to come at you. It takes practice, but time it so you can get as many last hits on creeps as possible. You will be farming lots of gold, but more importantly, 1 Ap per kill. By the time Baleful Strike is level 3, you should be auto attacking the ranged creeps 1 or 2 times (find out and time it) then killing them with it. This is the most consistent way to get creeps (with your mpen from runes, you penetrate through all creeps' MR until around level 10ish). Watch numbers for damage, because they are important. Once you get to level 7, you should be getting about 5/6 creeps per wave with Baleful Strike.

Early kills

by level 11, I usually have at least 100 bonus Ap from Baleful Strike. By this point, the items you want are: Tear of the Goddess, Boots, and Hextech Revolver. This gives you a largeish mana pool and regen for staying in lane, Ap for damage, and spell vamp to stay alive in lane. Between all of this, you should have around 150+ Ap. Your ult is lvl 2 with a 1.2 conversion ratio, it alone will hit for about 550 dmg, and baleful strike is hitting for about 350. In general, if you Ghost, Baleful Strike, follow them!!!, Dark Matter in front, and Event Horizon, then Baleful Strike, ( Primordial Burst if necessary). Either way, guarantee the kill. Take a tower hit or two if needed, then return to your farming. While they are gone, you should heal to full hp, kill a wave or two, and proceed to begin ganking / KSing in other lanes.
If other people come to your lane, make sure you get the kill and then tell them to gtfo your lane.

Your Ap growth will be slowish until you can 1 shot creeps, at which point no creeps should NOT be hit by Baleful Strike (and die from it of course). When going to other lanes, wait in the bushes until the opponent is at low health. Proceed to Baleful Strike them, and Primordial Burst if you can; just make sure you get the kill. Leave lane, cuz your allies can push if they want. When you feel like it, grab your blue buff for more CDR and mana regen. Shoot any and all low creeps you can for more Ap (Once you can one shot them, this becomes kill every creep you see).

Team Fighting

Continue in this fashion until team fights begin to happen. Once they do, it goes like this: If nobody is targeting you, Dark Matter in the middle, and hope for luck. Start throwing Baleful Strike at whoever is low on hp, and if someone hits around 1/2 hp, throw Primordial Burst so you get the kill. (try to double up your ult with a Baleful Strike just to be sure). Again, continue until you have your Deathfire Grasp.

Now, you can 2 shot their ad carry, so just walk around waiting for people to try to fight you. If they have multiple assassins, stick with someone on your team so you have a meat sack to pull hits: someone squishy who makes a big target like teemo is a great choice. When they try to gank you, use the active from Deathfire Grasp on the most threatening of your opponents, and then ult them. (One down) now just stun and throw Dark Matter and use your Baleful Strike alot. (By now, it is enough to 4-5 shot anyone on their team) Running away until you can rinse and repeat can mean lots of kills. If they are going to target you melee range, just stand still and throw Dark Matter on top of yourself. If they stay away, you will kill them, if they come close, you will kill them.

End Game

By end game, you will have well over 1k Ap and your ult will be closing on 2k damage for most heroes (Ap champs will be more), and DF-grasp will be hitting for around 70% life. You can now just about 2 shot their tank, but that is a waste of time, so go for the fast people first. DF grasp and QQ (double Baleful Strike) their carry until he actually Q-Q's, and then ult their AP champ (you just got a double kill). Now throw Dark Matter on the rest, and lay down Event Horizon so they can't run. From here, you can almost 3v1 and win every time, so you are the Tiny Master of the Universe. So to show your appreciation to the chumps who acted as meat sacks while you reached your new found awesomeness, push as many lanes as you want alone. (Because you don't need them) However, try not to let any of them get kills as that would **** your style.

Veigar is the biggest, baddest AP stacker in the game. My item build is fairly simple, but I will explain it later anyway. The most important part however, is not in what your build looks like, but is in how you play the game. Lulling your opponents early game into a false sense of security can lead to easy early kills, which will mean easier late game kills. The trick is in the mentality.
When you focus on simply farming creeps like a madman, and save your abilities for team fights, Veigar has the ability to have almost exponential growth WITHOUT ACTUALLY NEEDING KILLS. Although kills are nice, you get tons of gold and AP from creeps when you learn to harvest them with Baleful Strike, and in the end, you can just wander around killing creeps and anyone foolish enough to fight you won't realize that you have gained 50 Ap since the last time they saw you, and you still haven't gone to buy yet.
Kill heroes when you can, (sometimes going 1v2 for a double kill suicide is worth it; that's for you to decide) but most of all, don't let creeps see you without adding to your AP pool.

NOTE:

the shown item order is NOT the preferred buying/finishing order.

Sorcerer's Shoes:

This is standard: more Mpen = More damage.

Archangel's Staff:

Large mana pool; nice AP; Nice mana regen.

Will of the Ancients:

I am addicted to this item, and I have had a bit of laughter over it on veigar, but here's the thing:

Baleful Strike is used every 3-4 seconds. It heals for at least 100 hp once you have this. Meaning: early game it takes 10 shots to heal you to full hp (about 1k hp). Let's see the other mid champ match that life gain.

Dark Matter has 1/3 healing. endgame it hits 1k dmg per target (1/3 of 250 hp. . . per target.) meaning 1 shot will heal you 1k hp if you hit 12 guys. ~500 hp gain for a creep wave. That is really nice.

Considering the sustained damage you have, and also the nice heavy hitting abilities, this can let you hang around a fight where you should be dead: worth it.

Deathfire Grasp:

this gives you a little Regen, CDR. . . and an active that gets bigger the more AP you have. If only you had lots of that. . . OH WAIT! 1k AP means 70% of their hp in one shot, and you still have your ult. . . =D

Rabadon's Deathcap:

This rocks on good ap stackers. You get free Ap, and tons of it, and this makes every 100 free Ap you get turn into 130 free Ap. Good deal!

OPTIONAL

Your last item wants to give you Ap and mpen, so you have 2 good choices depending on your enemies.

Abyssal Mask:

if they have their own heavy hitting AP champs, and less MR overall on their team. i.e.: squishies

Void Staff:

If they have lots of MR this is what you want; for obvious reasons. =D

Kill-Stealing Like a Boss

As much fun as Kill stealing is with the average champion, it is most fun as Veigar. (And it is possible without hurting your team!)

I hope you enjoyed my guide, I know I enjoyed making it, and I REALLY enjoy playing it, so feel free to try it, comment, enjoy it, and piss your team off during every team fight, while pulling the game in your favor regardless. Enjoy!