Playing as glacial shen support
the purpose of this rune pick is to allow shen to be picked into a wider variety of champions than he currently is. In high elo shen is currently seen as a counterpick to leona and other melee engage supports. While aftershock into engage melee supports is in my opinion superior, This rune choice allows shen to be picked into ranged matchups he otherwise struggled with. Glacial can be picked into melee supports that run guardian as well, but some extra caution is definitely needed as melee supports that take guaridan like braum specialize in peeling and can turn around your 2v2 engage.

The multi target slow from glacial augment provides teamfight control as well as additional gank setup in lane, as well as allowing for enhanced long trade potential on shen taunt. The low cooldown of glacial augment allows for multiple uses during a teamfight, while the itemization allows for shen to have surviviability in extended fights even with the lack of aftershock.

As glacial shen support you are squishier than with aftershock but have better gank setup and roam potential. Roaming mid/participating in early jungle skirmishes is where this pick shines. After getting level 6 primarily look to use ult to turn fights around the map much like shen top, but with the added condition that you should try to not TP in a wave position that will compromise your ADC in a 1v2 situation, also constantly playing in a position that is safe to not get cancelled gives up all lane presence and will leave your ADC vulnerable. Honestly I prefer to use it to enable dives bot lane with jungle/mid/jg+mid (goon squad time :D).

In teamfights you operate quite well as a peeling support, taunting the closest priority target your damage dealers are in range to follow up on. Prioritize controlling the teamfight with glacial augment procs, but after zhonyas especially feel free to look for engages on backline.

LOCKET OF THE IRON SOLARI:
-For mythic options I pretty much exclusively recommend building locket for the main reason that it works well for peel and engage and is thus more flexible than evenshroud and much more forgiving.

ANATHEMA’S CHAINS:
-Item is not balanced stat wise it gives enough HP to compensate for its lack of resists due to your tank build with locket and defensive boosts and putting the chain on the main source of damage you are getting hit by adds to the tankiness due to the 30% damage mitigation. The tenacity reduction also means your taunt and slow last for longer. Main second item option unless vs. low damage team comp on enemy team.

REDEMPTION:
-The utility of this item is too good on shen that it doesn’t matter if there is lost gold efficiency from the base mana regen this item provides. Along with the long range AOE heal and damage the shield increase synergizes with shen Q and ult along with Glacial Augment slow, as of 11.24 this ratio was buffed so you help your team set up skill shots even better. Depending on the game I sometimes build this before anathema’s if I am not being focused and can afford to play mainly as a peeling support.

ZHONYAS:
-I really enjoy the utility zhonyas brings to shen support later in teamfights, as it allows you to dodge ability damage and stall for your own cooldowns which can exert a lot of pressure on enemy backline when you are tanky enough to taunt aggressively. I have done more testing and think that it should be built later into the game after you have enough HP to make use of the resists it provides. Locket->Anathemas->Redemption->Zhonyas with tank boots makes sense to me. For heavy AP I think Zhonyas is less of a priority and other items should be looked at. Also relatively expensive so other items are often better when behind since you are not going to be able to zone in fights when your team is getting demolished.

-After further testing I have stopped going perfect timing (stopwatch) in inspiration tree most of the time as it only contributes 250g to Zhonyas item completion and I was consistently finding more value from hexflash. Two 2v2 assists from a hexflash engage that otherwise would not have been able to have been done otherwise already provides more value than running perfect timing, not to mention the zoning pressure in lane it provides and the cs denied from having that pressure.

MIKAELS CRUCIBLE
- Mikael’s Crucible is honestly only good into heavy magic damage if you can get value from the cc removal active. The item itself provides extra shielding and magic resist, but active items always have part of their gold efficiency tied to the active it provides. If you cannot use it there are better magic resist items to build. Having the added slow for glacial does not compensate for not being able to use the active well in my opinion but I don’t know the exact math on it. Currently looking around to see if someone has already run the math on how much gold is sunk into the active.

THORNMAIL:
-The winrate of purchasing thornmail relatively early on shen support after mythic is actually suprisingly high. The increased healing reduction on immobilize is used well on shen with a 7 second cooldown taunt when fully maxed, but I think part of the reason the winrate is so high is because the data is being skewed by all AD teams getting countered by both armor and heal cut. I recommend vs. all AD teams with at least one lifesteal drain tank, but even if you are building it as only a form of heal cut I think having the upgaded thornmail is better than sitting on bramble after the nerfs to bramble vest a while back.

FORCE OF NATURE:
This item is more expensive than abyssal, but the tank stats it gives along with the movespeed is worth the price. Even as support if you need a lot of MR I would recommend this item. Mikael's Crucible has some merit because it is cheaper and has a valuable active ability, But in terms of raw stats and ability to tank I think force is better.

KNIGHT’S VOW:
I like this item late game due to the sustain it provides if your ADC/main consistent damage (thinking of cass mid or ryze), as well as having enough health to tank additional damage when you redirect a portion of damage they take. Item can certainly be picked up earlier than before especially if you have a fed ADC and they are all you care about protecting since they will deal a lot of damage and therefore heal you for a lot of health. If you pick this item up I would skip zhonyas since you want to be out of stasis in order to be healed anyway and your job now becomes much more peeling focused than zoning backline in fights.