CC - Crowd Control
CDR - Cooldown Reduction
OP - Overpowered
CS - Creep Score
AoE - Area of Effect
DoT - Damage over Time

Any new swain giving him a shot can clearly see that swain is an overpowered killing and rooting machine. This is one of the characters in the game that i just picked up during the free week, and instantly loved his carry playstyle. The contents wherein are here to give pointers to new swains and veteran swains alike. My playstyle might not match that of yours, but an aggressive swain can - and will, win team fights.

Pro's

-Works best as a soaker for damage.
-Deals insane damage to single targets, while controlling multiple targets.
-Very high spell vamp from Ultimate Form.
-Combine W>E>Q>E>Ignite = First blood 100% of the time.
-Can set up roots with Q, equaling crazy CC opportunities.

Con's

-Runs out of mana very fast with Ultimate up.
-Can be zoned out by AD ranged carries.
-Has no true escape besides a flash (although why would you, 75% health return on ultimate, duh).
-Too Much fun to play.

These runes will work as mid lane runes or solo top runes. I see swain as a great solo top, however, AP Nidalee(lets not even mention AD Nidalee) and Annie are better choices for solo AP Laners. These standard runes should be kept for most AP carries. Quite standard. Standard.

THESE MASTERIES ARE VERY SITUATIONAL, HOWEVER, IF YOU ARE PLAYING NORMAL MATCHES (unranked) THEN THIS IS THE PAGE YOU SHOULD USE

The only other choices i would see fit would be a 21/9/0 build. Only downside to a Vet. Scars build with the masteries is the fact that blue buff is a complete NECESSITY for team fighting on swain for extended harass and duration, but I will get to that in a bit.

The items i aquire on swain usually scale with the other team's defenses / strengths.
is the choice you should build before you build your complete Rod of Ages. Simply because, you can move faster, and penetrate through the m. resist that they have.

On those pesky AP carries and, occasionally, AD carries that sometimes wander into mid lane, complete your rod of ages before you complete your boots.

By this point, you've already become a HP hefty [But not a tank...] swain. This is good. Now you need to hit hard. Rush for that rabadons. By this point in the game, you should have gotten a kill or two, and should have plenty of money.

As soon as the rabadons is done, you will need CDR in order to cast your 10 second CD moves signifigantly faster. Fiendish Codex - Perfect!

From there, become OP and build a Will, or if you have a very CC lacking team, grab an Hourglass first and become an initiator for your team.

There are two ways i usually build swain, however, in both of these builds, I ALWAYS max Torment (E) first. Always.

The recommended way that i use is to build the root first. Most good junglers will come mid for a gank at level 2 to try and snipe off an unsuspecting player. Good 4 You, you have a root. Flash in at him, root him, E + Ignite, lee sin kick to face for KS, all is good, right?

On a serious note, Nevermove allows you to aquire multiple amounts of farm(CS) without having to be in Zone of the person who is getting their CS. Also, since your passive gives you mana per every kill aquired, the cost of using this spell for 2-3 cs is not that bad of a tradeoff.

Most of your damage as swain comes from the rediculous amount conversion of his Torment, which does not require them to be in range of your champion, unlike the Decrepify, which requires the champion to be near swain's rabid bird.

An Additional Way to Swain

You can aquire Q first, and then E, and get W at level four, and max both E and Q at the same time simultaneously until both are maxxed at level 13. This build focuses more on harass, but does not have the scare factor of a root on a solo laner early game. Both builds are quite legitimate and are feasible for whatever playstyle you choose.

THERE ARE NO VALID ALTERNATIVES FOR SWAIN. NONE.

Now that i made that clear, i will gladly hear opinions as to what others you would consider.
However...

Ignite + two other dots is a guaranteed kill, and will definately make your opponent very mad.

Flash is the perfect escape over a wall, and is also great for catching someone off guard into your skill shot W, or to chase those down in CAW CAW form.

Any other summoner spells on swain do not aid his power and should not be considered.
Heal - He has an ultimate that does just that.
Clarity - Dat passive
CV - Get a support already.
Ghost - Mmmm...maybe. Not as scary or suprising though for those mid game kills.
Teleport - Possible, however, both of the two selected weigh much more over this. AD carries need more farm anyway.
Exhaust, Promote, Cleanse - Alt + F4

Gentlemen, before you teamfight, please go and aquire your blue buff. It will give crazy mp5 and allow you to stay in Rabid Birdy form longer. Also some nice CDR with it too.

Alright, the fun part. I will post up a match or two of LoL Replay games if requested, but the way to play swain is to utilize his absolutely ANNOYING AoE ultimate with someone on your team who is competent with Crowd Control.

Situation 1

If your team is lacking a tank, You should have gotten an Hourglass. Good Job. Now what your job to do as Swaitank is to find that over extending AD carry right by your turret who thinks that your W wont do anything to them. There are a lot more than you think. You honestly dont have to even get them in turret. As soon as you have someone squishy - anyone, caught in your roots, go ALL out and ping a few times if your team is slow. Do this by combining some dot spamming and blowing the ultimate right on top of them. Once you get to the DoT spamming phase, this person will already be dead. Your job is to now scare the absolute **** out of the team by charging headfirst into their team while being a devious, rabid raven. Flash forward if you must to aquire a kill for your team, but make sure to SAVE YOUR HOURGLASS. This will allow your team time to catch up to you and save you in time. Your spell vamp is so rediculous that you will be able to survive as you come out of Hourglass.

SITUATION 2

You have a tank. GJ! You know what team comps are and stuff. Now that you have a tank, you do the exact same thing as listed above, except this time, you dont have an Hourglass, you have your flash. Your job is to bait once you are low back into a tank's moves, or if playing with someone such as Lee Sin who can teleport to you with his Shield, keep moving towards the enemy to ensure a kill.

When not playing in a total team fight, there will be those scuffles that break out in the jungle. Swain will win any 1v1 with his ignite up, [unless its a Gangplank with 12 kills that was fed by your garbage soraka]. At a certain point in the match, you wont even need ignite anymore, you'll be so fed.

NOW, saving people with your W.

Usually people will desert a low HP person that is in the woods running from an entire team. Except you are Swain. Place down a W right behind the Soraka and watch as she sees them get rooted and runs in to try to kill a 12/0 gangplank that you rooted for her. Seriously though, it is a great tool to get people off of someone.

Generally though, you do NOT want to use your Q to help someone escape unless you know that you can kill that champion and whatever might be behind them. Do not be a feed swain. He's too Overpowered for that.