This is my guide on how I personally play tresdin, the best thing about this hero to me is she is not a hero in a bikini with a tiny sword, this chick is full plate with a giant pole arm that just flat out tells you, you are about to have a very bad day.
Treated right, not like a lady, but with an attitude of if you hit me, I will hit you back, and I hit harder, this is one of the hero's that if you try going blow for blow with you will fail, you will fail badly.
She has the ability to chase, hard disable and out damage any right clicker in the game, I have had games where 3 people thought they could trade hits with me and steam roll me, they didn't make it.
This guide will not contain purdy pictures, just simple things I have personally used tested and found to be effective and informative.
This guide is post patch, after the multi strike lifesteal, and I still love her snowball skill.
Generally I hate this part as pointing out a hero's weaknesses as it is just frankly depressing, this is the one hero that I can honestly say doesn't have any glaring weakness that cannot be covered by Items or simple intelligent application.
-Low armor and Agi gain
-Massisve threat, perhaps the biggest in the game, you will get focused down the second you show.
-Long cooldown nuke/chase mechanic with variable damage due to creeps and hero's hit
-Bad duel decisions can cause the other team to snowball, you give lifestealer a duel and you will get raged at.
+ Decent move speed
+ With duels can become the most damaging hero in the game, nothing can match you
+ Can lane anywhere with anyone or with no one.
+ Insane life steal reactive
+ Call removes disable effects, adds a tonne of attack speed and very nice regen.
Starting off buy yourself a tango, clarity, armor ring and a stout shield.
You really do not need a salve with her at all, your call does nearly the same effect as salve making mana regen more necessary.
The stout is needed as you will take harass in the lane, and you will even cause intentional creep aggression for added damage and harass on other melee hero's even ranged if your faster, the armor ring is so you can pick up your first item that keeps you going, your basilius, armor/damage/regen.
With this you can keep up your shout without just as a emergency button, cheap upgrade to an aqua for added stats.
Next is your boots, some people prefer phase, but really the extra damage is out weighed by attackspeed, health and tread switching.
Once you have these you can easily win a duel against a lane, nuke, shout and duel, always start a duel with shout up for the best chance to win, regen with mega attack speed is a good thing.
Next is your tools of choice to gank with, you are a gank hero, any time your duel is off cool you must go looking for duel to snowball.
Your choice is between a Shadow blade and a Blink.
Personally Shadow blade has a blink beat by far, added damage, attack speed and undetected you can lockdown and KILL the greatest threat before they wreak your team even then you are not the initiation you are the clean up.
Now I have heard the poor argument you can get countered by wards and dust, but what the hell are you doing running into 5 people alone for anyway?, are your supports not dewarding?, they cannot sentry and ward the whole map, and even if they dust you, remember your not running and your not alone.
Now the best damage item for tresdin for me is desolator, the added damage and armor reduction can when combined with your shout can melt some hero's before the duel ring even comes up, the armor reduction is reliable, and your constantly adding damage, death for a duel win can be debated as a fair trade especially if you kill there hard carry or a major team nuker like lock.
Armlet like on naix is very effective as you will life steal, and you will life steal for a lot depending on what level the skill is, added damage, health, attack speed and armor for health degen, that can be over written by a leveled shout for some duration, very useful.
Crystalis does not need to be upgraded if you don't wish to, your base damage will skyrocket with duel wins that it BECOMES a daedalus, of course if you get the gold get daedalus, no such thing as too much damage.
A basher is an effective item to use on any melee right clicker, nothing more annoying than having someone just run away from you, lets be honest its the best idea you can have if you see tresdin running at you and you are alone or have no stun.
A heart on a strength hero is always a good thing, massive regen, great health and damage added, no honest reason why you would not get one if you have the gold.
Assault Cuirass is a must get on tresdin, this makes up for your mediocre armor and adds on an armor buff and debuff aura, added with someone with a vlads or just your basil/aqua ring can add some serious tankyness to your team.
A Black King Bar is vital in games you know to have alot of hard lockdown, little added damage is nice but magic immunity is better.
Side note do not build lifesteal or get a rapier on her, its more or less a waste of a slot, your duels can get you a free rapier, and you're reactive 80% is far more than enough.
In the conclusion once you start packing on the duel wins, you can even chose to remove damage items and go for more survival items if you choose to.
Friends of tresdin are the one's who start the fights for her, or ones who can improve her ability to fight and win a duel.
Omniknight: slow aura, flash nuke/heal and a long lasting bkb and his ult?, this dude is tresdins secret lover, with him on your side you have no way to lose or die in a duel.
Dark seer: Bro who gives you super speed and an ion shell, you can forgive his ion spam with this.
Tiny and Tusk: Toss or Snowball is a great thing, i'm next to you, your hurt, all that is left is for me to act like a lady and shout at you then beat you to death.
Wisp: Relocate, Wisps and tethered over charge, nothing to see here, your dead.
Pudge who can land his hook is a great thing, added damage for you, flesh heap for pudge, win win.
Extort invokers: if you cant land a sun strike in 5 seconds, I'm speechless.
People to watch out for as tresdin are the ones who can ruin your duels or simply stunlock you.
Dazzle: Learn to hate a good dazzle, grave instantly stops your duels and can cause you to feed a duel.
Bane: Nightmare just stops your duel cold, enfeeble makes you do nothing, and his ult = death, hate bane, hate him hard.
Chen: Having your duel target teleported out can be slightly embarrassing, as you tend to try chase that hero.
Earth Spirit: your target just got pulled out of the duel, and here is a rock to the face.
Earth Shaker: stun, stun, mega stun, stun.
LINKENS SPHERE: Duel just got wasted, take a moment to take this in.
I always start off with life steal over the shout, you don't have the regen to keep it up and there is nothing more painful to another laning melee than to get hit with than a life steal proc, even more so if it is a squishy ranged hero.
By level 2 you should have had a wave or two of creeps to get your basil, now you have mana for shout heals.
This is the boring part of your game, farming and harass as needed, the great thing with tres is if they lane looks too dangerous to farm, you can walk into your jungle and take the large or small camp with a shout with no issue.
When 6 comes around then is your time to win your lane and kill everybody, first rule of legion, never open with duel, never ever open with it, nuke, hit, shout then duel, make sure you tell your lane partner what your doing or you might just walk out, do nothing or worse just feed a duel.
Be aware that this hero is axe with higher survival, so if two or 3 people try to right click you to death, stand and fight, judge if you can get away and if the even think for a second you can not, shout and return fire, the aggressiveness can force people back or kill 1,2 or all of them before you go down.
Now the fun begins, this is where you either become a carry or become dead weight, if you have not won a duel by 11 then your going to be terribly weak.
If you farm up a shadow blade quick enough you can sneak in and 3 man lane kill, 10 permanent damage is well worth a death, though 3v2 that is not likely, make sure to communicate that your killing someone with a ping or talk.
Think of duel as a track, each point of damage is 50g 500-700-900, add on more if you get the kill or assist gold.
If you can't get someone in a lane, call for help, and if the other team has gone 5 man hard, you can fight with your team and make a impact, level 2-3 nuke can really hurt added on the regen don't be afraid to go conan style and swing away.
The second you have your desolator no hero in the game can deal with the raw damage you throw out, roshan becomes little more than a creep, shadow blade with a deso hit shout and duel kills anyone instantly who is not a hard str hero, you might even kill some supports before you can even duel them.
I do not like this as a primary choice of leveling, any team with even a ******ed baby monkey will realize she is in there, and you rely on proc's and shout, the second your lane hits 3 and sneezes in her direction kills her.
Not to say you cant, just don't, slow, high risk, brain dead easy to stop and leaves a lane to free farm.
She can clear a camps rather quickly but I would only recommend doing this when you have a second or two to spare, or the lane is pushed to a tower.
I will add in bits and pieces as comments or questions come about, but as it is, i cannot think of much else to say about this hero other than she is soon going to replace my crystal or silencer as my 3rd-4th most played hero.
No one replaces meepo for me though.
Enjoy and comment as you chose bro's!.
Drums: Cool item, cheaper ultimate orb with a speed aura, easy to collect, and a good item, though you need to focus on hard damage or survival, a drum is better served on someone else.
Orb Of Venom: A cheap and easy slow, Legion is already faster than most hero's so chasing is not a problem, still a fine item if you think you need a little more catching power.
Satanic is very ineffective, life steal when you life steal and it costs a tonne of gold, would you prefer a satanic or a AC, you already have a beasty life steal.
Medallion is most certainly a good item, cheap and quick to collect, but I do not like to slow my core unless I know i have someone who can set up a fight, and lets face it, out side of stacks your not going to get someone who will feed you a hero when they can "try" alone.