Hello guys, this is my second Guide on Mobafire. I am German so my english is not very good, but i will try to do my best.

Why Shen?
You should choose shen, because he is very good for playing with a partner and useful in early/mid and late game.With his ulti he can save friends, and ports next to them.
so he turns the battle on lanes from a 2v2 in a 3v2 or a 1v1 in a 2v1.Then he can charge and taunt in one, and your friend/s can deal a very large amount of damage.

Pros:
-can Taunt and Charge in one
-do much dmg with passive and Vorpal Blade
-very nice Ulti
-he is a Ninja
-nice doctor skin

Cons:
-!!!very very very high energy cost!!!, you die sometimes because of that or dont get a kill (but with blue buff its much better)
-hard to play against Kog Maw, Malzahar, Amumu or somebody with madreds.

Greater Mark of Insight: Very Useful for your first. I think it is the best Mark for Shen, you wont need AD, AS or ArmorPen.

Seal of Vitality: The more life you have, the more damage you deal with your passive.

Glyph of Shielding: I think the extra MR is better than CD or something else. The CD of "Q" is low enough and you wont need CD for the other spells.

Quintessence of Fortitude: The more life you have, the more damage you deal with your passive.Really!

Teleport: Its always useful and I think you need experience and your team needs your help, with your Ulti you can be port to bot with tele, and can port to top with ulti :D
Ghost: Its good for escape and mainly for get in range for taunt or something else.With Force of Nature and ghost youre also very fast !

What you can get too:

Ignite: If you want it, get it. I dont need it and think Ghost is better, but Ignite is ok.

Flash: A good option to Ghost. And you can charge through wall flash thorugh wall and the Ninja is away ;).

Cleanse: In my Opinion Ghost or Flash is better, youve got Mercurys thats often enough, but if youre scared of stuns or Nasus annoying Slow, you can take it.

Fortify: If you activate it , skilled the point in masteries and taunt them at tower, it is funny to see how fast they are down :).

0/21/9
Why no Magic Pen for "Q"?
Because I think the points on Ghost and Teleport are very important. Also the experience boost and the 1 gold per 10 second is good, and more important than the Ability Power, extra CD and 15% Magic Pen. And the Magic Pen of the runes are enough for him.
I think the defense tree is self-explanatory.

First you start with a Ruby. Dorans shield is good, but i think with your "Q" you���´ve got enough Health Reg and the Ruby is the first step to Warmogs. After Ruby, you go back if you can buy Mercurys, if you must back before, buy boots first.
After Mercurys you buy Giants Belt, then Warmogs. Why Warmogs? You do more Dmg because of your passive! Also you survive much longer in the beginning of the game with HP, and not with Armor or MR.

!Important!:
After Warmogs you buy Sunfire or Force of Nature, depending on the situation.When buying Sunfire first Chainvest, when buying Force of Nature first Negatron Cloak.

If you bought Sunfire AND Force of Nature, you buy Guardian Angel.

After that you buy the second Warmogs: youve got enough Armor and MR, so you need health. You also do more damage because of your passive, did I mention?

If your both Warmogs give you max. Health youve got over 4,5k HP, 200 Armor and about 200 MR. Much Fun !

I go Q-E-Q-E-Q-R-Q-E-Q-E-R-E-W-W-W-R-W-W. I dont skill "W" first, because I want to have got the taunt as good as possible. In early game you can kill enemys very fast if there is a Ashe, Annie,... so they shouldnt move as long as possible.Also you can help teammates very well !

If youve got problems with this skill order, play more defensive.
So go Q-E-Q-W-Q-R-Q-W-Q-W-R-W-W-E-E-R-E-E.

This game need 35 minutes, I bought all items and killed the most and did the most assists. They were very squishy and then they had no chance when they were 3.
I did 2 triple kills in team fights, tanked towers saved often mates and killed then an enemy champion and much more.

After you played a few matches, you know when you can attack and when not.
You will learn to use ulti better and to assist your teammates.With this Build youve got much HP and do much Damage, and I think you dont need Item Options, I every time play with this Items and I am ruling.

Much fun, rate and comment Please and if you have Tips or improvements, say them!
Thank you for reading this guide.