This build was made for taking down multiple opponents at once, the more creeps there are near where your fighting the higher your chance of survival. Swains ultimate gives 75% of the damage dealt per 3 crows making him a walking tank mage. The opponents will often focus fire you, be wary of this as even though swain has amazing amounts of spell vamp if focused the damage is too much too take with no defense. This build can be suicidal, and the way this build is meant too be played is situational, team fights you should be the last one in the first one out after rooting the enemy team and damaging all around you.

Pros
-Exceptional amounts of survivability late game
-Can easily gank on his own
-Can survive encounters with 2 or more champions on his own
-As of level 6 can take down champions on his own
-Torment increases the damage done by ignite
-Swain has a bird
Cons
-Squishy early game
-Mana pool issues all game (Swains ultimate can drain your mana pool in under 1 minute.)
-slower than other mages due too his cane

My reasoning for the runes i choose was because of Swains ultimate which drains mana incredibly fast, and the others were chosen because of the additional ability power for his abilities, although they are all interchangeable with anything with added mana regeneration or ability power.

Swain is naturally slower than other champions and the added speed boost from the masteries could save you added mana regeneration too compliment swains ability too diminish his mana pool too almost nothing. as well as the added spell penetration too heal more and cause more grief too the other team. The added ability power from ignite being ready too use is an added bonus as well.

The item selection that was chosen was too compliment swains abilities, first off by giving him a bigger mana pool, and allow swain too regain mana by leveling up. Will of the ancients is a necessity for this build as it gives swains ultimate a spell vamp of 100% as well as the 25% for all other abilities. This build could be played with getting the holy chalice first and abstaining from getting the rod of ages, it is possible too replace the rod of ages with any item that gives ability power or magic penetration

Torment is your give all for damage, not only does it cause damage over time it increases all the damage you deal during its duration by a percentage.

Nevermore is amazing for helping too gank all game by snaring the opponent for 2 seconds, there isn't any point in leveling it until its the last ability left, the cool-down does go down however generally if you miss with first nevermore your not going too get another chance too use it on the same running champion.

Decrepify is possibly the most useful ability as it deals damage and slows allowing nevermore an easier target, leveling this is essential as it can help bring a running champion too an almost standstill while taking massive amounts of damage.

Ravenous Flock is the most powerful ability that swain has, it has a 75% spell vamp on its own, and if you can get ahead of a champion it is possible to be targeted by their towers kill a champion and still get away.

Ignite is amazing for swain as his torment ability increases the damage dealt by ignite, allowing for easier kills for running weakened champion

Flash is for getting away from a situation where they focus you, or for getting into the thick of combat before the other team knows whats going on, while dropping evermore and decrepify on the nearest squishy as well as going in with your ult going

These could be replaces with

Clairvoyance for the added mana for swains ult, allowing it too last that much longer or getting you out of a tight spot being chased with no mana too activate your ult for that last second health boost before your towers

Ghost is also an excellent choice as it will allow you too enter combat, easily chase someone down, and run away if needed, it is the perfect for certain play-styles

Try and get last hit kills with swain which will in turn increase his mana pool by use of his passive which replenishes mana by the kill. Swains ultimate is also a really good use for farming and getting mana back as long as its not active very long.

During team fights attempt too hand back for a bit and then jump in out of no where with your ult going slow the nearest squishy and then snare them, this will almost always guarantee a kill if the other team is running.

Early game when laning with someone nevermore can help you score a kill by snaring a enemy champion by rooting them too close too a tower too run out of its range, or for an ally too catch up to them.

Other builds for this character don't have as much damage output with his abilities, going more for the survivability, although late game this build I feel far supr***es any other in terms of survivability while still retaining the damage output, this also makes him harder too play and not die until around level 14 however at that point you should be able too melt faces wherever you go

This is a good build for those that just wanna deal large amounts of damage in a medium amount of time, while being able too chase an enemy champion directly too their towers while still slamming then with ability after ability.