this is a build for if your team really needs a good tank, don't suspect a lot of kills, only a lot of assists. With this build you are always the best at 1 vs 1 and you can somethimes also defeat 1 out of 2 when it is 1 vs 2. But remember this is supposed to be a support build. I played a real lot with shen and i tried a lot of bluids, this is the best build i think there is for a support tank shen.
pure build for taking and absorbing damage, if you want you can change the utility section to ofense so you have some cooldownred, MR-pen, abylity power and something else, but i don't find it worth it. and with utility you get your ghost upgrade with extra exp, gold and regen
ghost: real handy to get out of combat just in time or help an aly if your ult is on cooldown
ignite: just the thing that can make the kill, or help a lot in team fights where there are health tanks or just tanks, and also for example against swain his ult.
just quick and short, you need vorpal blade in the beginning because you can get a kill together with your spells. Then you need feint to take some damage because they will probably focus on you because you are in the front line attacking melee. At last the "shadow dash" so you can get away if needed, because you aren't a tank in the beginning. after that it is always improving your vorpal blade and feint because they are usefull in battle, you don't improve your dash so much by leveling it up, you only make it cost 5 less energy and 0.2 sec extra taunt every upgrade. (not worth it if you ask me)
The runes are all for having a better defense and lasting longer, you can really use the extra armor because they will reduce incoming damage by 5 (DPS) and 4 (MR) percent. also the extra health comes in handy when going trough the levels and you will be a lot extra stronger every level. I also made sure that it are all primary runes so nothing is wasted.
-some of you might find it strange to buy heart of gold in the beginning but it gives you extra money with good health and some armor, a good combination and you will need the bit of extra money as you will almost never get kills.
-For the boots, wel this is optional because if you want you can buy mercury's treads if you want so you will have more MR but i find it handy to be just a bit faster because when you use your ult to save somebody, most of the time they come after you instead. Yes you have your dash but it has 10 sec couldown and you probably use it on them to stop them from focuccing your teammate so you can't really hope it always saves you, so the 10 extra movement is handy.
-the sunfire cap is next because it good amount of health armor and it's 40 damage/sec effect. with that you can take easyer bigger waves of minions and come out unharmed and have a lot of money because you can farm easely with sunfire cap. The order of buying the armor or the health depends on the game you are in, if there are a lot of normal DPS you better buy the chain vest if there are more magic based enemies then buy giant's belt to survive better.
-i putted the mantle first because you will not have so much MR right now so first buy the null-magic mantle and then buy your way up to guardian angel. Its combination of good armor and MR speaks for itself why it is a good buy in the first place. But as support and with your ult, you risk yourself a lot so you can always die when chased by 4 or 5. So the special effect really saves your life when you have saved someone elses.
-after that you buy aegis of the legion to give you extra armor and magic resist and you help your teammates with the aura so you all do better in big 5 vs 5 combat action.
-after that you buy force of nature to give you extra health regen that really comes in handy after taking a hard beeting saving someone or after 5 vs 5 combat. also it gives you the remaining MR that you need because you won't have enough without it and you will be fragile against lvl 18 karthus for example.
- buy randuim's omen because you can use the healthregen and bit extra armor, but if really nescesary because there are to much migic enemy champs, buy "banshee's veil first, it gieves a lot of extra MR good health and its bonus of blocking a spel every 30 sec is a real life saver, i know you can't do anything with the mana, but that doesn't put up against the good parts of the item.
- also if you have DPS enemies, buy thornmail in stead of banshee's veil, you have less hp, but you really irritate them if they realize they are taking more damage then you without you attacking them
i hope you like my build, and remember it is a tank support build.