HAPPY NEW YEAR!!!

people are too harsh. what needs to be said has been said, but this deserves at least a 50% rating imo, so here's my upvote.

This build is pretty much like anyother shen build except for the Sheen, so why all the hate? and Aegis of the Legion is OP :P but it seems like u buy it way too late. I would give a +1, but your guide format is not so great, its just huge walls of text...

Just give the build a try and you'll see what I mean about it. It's not an overly expensive one and if you play heave harrassment with it and buy a few extra pots you can keep u and ur partner 2 levels ahead of your enemy lane.
It makes him a threat instead of an ignorable tank. VERY few games even get to level 18 that I play like this.

It's not that Aegis of the Legion is bad late game innate of itself. It's that a different item would be better. It's an interesting idea but I do think it could use some polishing up. I'll change my vote if you can really prove to me that it does work (stats? or something similar?) maybe I just suck at Shen.

Again this isn't a guide to being the normal blah tank that does nothing in game.
Feeding a carry is fine for a support like Soraka or the like BUT like I said that's not what this is about. The current Euro meta is boring and overused and not nearly as effective as having 2 offtanks in game as opposed to a full support that only heals people and makes team fights 4v5 if you're running against the former.
Aegis helps a ton to limit damage end game from the towers while you're crashing their base. It can mean the difference between winning and getting aced in their base and having the enemy team push you to end game during your 60sec respawns.
The armor only goes over 250 because of the 2 late game items which in turn become the most valuable at that time as opposed to health since nobody regardless of their Pen will be able to penetrate your Armor or Magic res to deal true damage which makes health not a neccessity.

If you get ganked by a Veiger or other slow AP mid then something is seriously wrong with your map awareness.

Another papertrail voter yay. Try before you vote and keep what "looks good on paper" to yourself as opposed to what actually works in game as described.
Sheen is cheap and a great mid game boost to get in essence 2 free attacks for every 2 hits.

Just as a rule of thumb, >250 of either armor or MR is bad. That said, Aegis of the Legion is built a little too late for it to be effective. Either build it earlier or don't build it at all. You lack health (which stacks with your passive), which you kinda need for a tank build. Otherwise you won't be that survivable. To aid in this, I strongly recommend something along the lines of Warmog's Armor or Rylai's Crystal Scepter. It's late in the build so nowhere else to really put the gold.

Mercury's Treads > Ninja Tabi. Don't care that Shen's a ninja.

Also, for your explanation for why not Shadow Dash, you said "Sure that will help your carry partner get kills before they're obliterated off the field but then what happens?" If your partner got obliterated off the field as you say, then you did it wrong. As the tank, your job is to feed your carry. If you max out your taunt first, then that means that Shen is doing his job by NOT getting kills, but by giving them to the carry.

Finally, there's the matter of Sheen. Sheen on Shen is kinda reserved for Burst Assassin Shen, which works, but that's not what you're doing with this build. If you want to do Burst Assassin, then stack AP and Health to bump up your moves and passive. Rylai's again is essential for Burst Assassin Shen. Not only that, but you are not runed for damage, AT ALL. Just don't use Sheen on this build. You don't need it and that gold is, and I quote, "Gold which is VERY useful elsewhere in the build since he's not a farming machine". For example, finishing your defensive core to make you tanky as hell and ACTUALLY ABLE TO TAKE MAGIC HITS. As opposed to, you know, being raped by an enemy Veigar or something.

Also, needs moar BBCode.

Ryalis costs 1800 more than sheen. Gold which is VERY useful elsewhere in the build since he's not a farming machine. You don't want more AP you want the passive of an extra 100% dmg on the next attack after life tapping. 100% extra every time means you can stand and trade with Tryndamere.
Against champs like Trynd and Renekton who utilize armor pen this completely neutralizes them.
Again try the build before voting.

Have you tried it out? Didn't think so. Trying the build before voting on it would make sense now wouldn't it? This build revolves around Vorpral Blade and it's damage\life tap instead of a measly extra .25 secs of taunt.
The abundance of armor comes from GA which is a neccessity to this build late game.
Then again you could work for the IRS and all you care about is numbers on paper.

i dont like your skill order, i believe you should stick with taunt before sheild and possibly before your throw, it seems with your skill order you will be unable to taunt long enough for it to be effective and sheild weak enough to be usless at the level you start finishing it off

i also disagree with sheen, your passive works well enough without it, if you want some ap go with rylais, it gives u slow with your throw, ap for ur spells, and hp for your passive.

Way too much armor. It's just NOT necessary.