Hello, European dropping in with my 2 cents.
summoner skills: ghost and.. fortify.
skills:Q,E & R. Do W last.
legion of ageis
leviathan, force a nature, sunfire, ect. This last item is situational.
ruby crystal: hp boost helps gank early game with taunt
ninja tabi: this is so much better then mercurys treads, the dodge will decreases your damage intake greatly during team fights and while pushing lanes.
frozen mallet: this will give you a major hp boost, this hp boost I believe is all you need until very late game. not only does it boost your hp astronomically, it gives a slow bonus. On shen who melees a lot can either be life saving or deadly. A fine example of this is when you're teammate is engaging an enemy, you ult him taunt then melee the enemy to death. They are incapable of escaping due to your taunt and slow. It also helps during team fights, you have just killed 3 of the enemies due to your fantastic ult on your teammate who was being focused. You see that sneaky kayle pop ghost and run, you pop ghost catch up with her, taunt, then slow her to death with your melee. Combined with your dash the slow on this is so friggin awesome.
ageis: helps during team fights, pushes ect.
guardian angel: you are not a hp shen, you are a defense/magic resistance taunt spamming shen. You are a ***** to kill, the enemy doesn't even bother to target you but you force them to by taunting them. This item allows you to act in a way you would not without it, you are able to be suicidal. If your team happens to lose a team fight or you're ganked this combined with dash and ghost is your escape mechanism. You die, they gather around you, in normal circumstances any tank would be screwed here. You revive pop ghost, and dash the hell out of there. Your taunt should take care of them stunning/slowing/caging you as players have a tendency to literally stand on you when you're dead to make sure they kill you. The cool down on this thing isn't a problem, you shouldn't be dieing every 1-4:59 seconds.
situational item: I suggest leviathan because if the game has lasted this long you should be winning team fights/ganks and are waiting to ace them then push. Sunfire cape is viable due to it being relatively cheap for the burst hp it gives and the fact it increases your damage output during team fights. If I'm strapped for cash I buy giants belt, the game usually ends there. If it doesn't I wait until 3k then trade my giants belt for a sunfire.