I have about 200+ games in with Silencer its been a long learning process so heres to me imparting some wisdom for those of you looking to learn how to play with Silencer. If you are here to learn how to counter him, GO AWAY!
I've seen people play Silencer and everytime its just not right, their build, their skill placement so god awefully wrong imo. Im not going to make a long story on how to play him but what I will do is throw down the basics and let you go from there.
As Silencer you will be expected to buy the donkey, get use to it and do it before anyone else does Silencer isnt a gold hungry carry and can more than afford this starting exspense. Your starting items is the initial components for building a mechanism and will help your passive health regen and once you get the headress your lane partners regen as well. If played right you shouldnt need any tangos or potions because with the extreme range of your attacks and spells you should be able to avoid getting hit. If you are having health problems because you are getting hit alot, you are playing to aggressive and quite possibly misclicking and moving to close, or being unaware of creep aggression.
Headress should be your first item built followed by boots going into power treads then a mek. You can decide for yourself what you will go next, but not getting this core starting items you shall discover yourself struggling quite severly with last hits, teamfighting, and survival.
For skills. I've noticed all other guides use a different build than I have come to use and sometimes its situational, but if played right Im certain my build can adapt to any situation.
Curse. It should be the first skill aquired and left at lv. 1 until you must put points into it over stats. Why? The problem with this ability is that it is ridiculously easy to counter. All the enemy has to do is cast a spell, and some heroes wont have any problems doing so. Save yourself the annoyance of wasting points into this skill early and watching your opponent cancel it everytime by only using it as a strategy. This is important......
When you come to the lane immediately target the enemy hero with less life casting your curse followed with auto attacks, DO NOT CHASE. This is going to hurt him, and will make him think that spell is more powerful than it really is. This is important, because this is exactly what you want him to believe. You WANT your opponent to cast a spell to get rid of it dwindling their mana pool. Eventually they will start taking the damage, realizing that it actually doesnt hurt all that much and believing its even better to take the damage/mana loss than waste mana needlessly on a spell (depending on the type of hero). If you are observing this, you are right where you want to be! >=)
By level 3, you should have 2 points in your Last Word, and you should NOT have used it at all. Let me repeat this, DO NOT use your Last word until you are CERTAIN for the kill. Why? Your opponent will have gotten comfortable with the curse assuming he is in no danger when he is low life. Letting your enemy know to soon that you have that spell in your arsenal makes him aware of the burst damage before you have the ability to surprise him. All to often do I see an enemy completely oblivious to the fact a last word has been cast on him sticking around to trade Silencer blow for blow only to realize 5 seconds later of their mistake. Often times players will even confuse a Last word cast for a Curse cast and try to break it by casting a spell, which works in your favor anyway if you are saving your Last Word for that untimely surprise.
I usually get first kill using this strategy in 90% of my games. After the first kill or maybe even two or three, your opponent will become aware of what exactly Last word is and will quite literally be scared and start playing extremely defensively. This isnt what you want, and what you want to do is lane change or roam for a gank, because guranteed the other players arent aware of it, and if there is an enemy low on life dont hesistate going in for the gank initiating with a last word and if they run - a curse. You'll be surprised at how often a kill comes in 5 seconds later.
At least by lv 4, you want to have a glaive to start accumalating intelligence as this is what will make you godlike toward your endgame if you've done well on kills. Like curse it shouldnt be leveled until after, curse and last word or maxed, because of its surprise factor.
Global silence should only have 1 level until like level 20 dependant on how large your mana pool is, if I dont have at least 1500 mana I dont level it past one due to the HUGE mana cost of the spell. Combined with you throwing glaives of wisdom at 15 mana per attack, a maxed last word and a maxed curse, you will find yourself barely able to cast your lineup if you level it to fast.
Thats it, hope this helps, goodluck and remember curses late game are for fleeing enemies and last word becomes your harrass spell. Have fun!