By using Fafs suggestion in the comments section of tellmewhen in Curse.com (http://www.curse.com/addons/wow/tellmewhen#c6117), i managed to make a meta icon showing the ring buff, whether you or someone else uses it, and the item cooldown. Posting it here for the community.

You need 3 icons to make this. 2xHidden and the meta which will show the info from the hidden ones

First Hidden Icon

^1^T^SShowTimer^B ^SOnlyEquipped^B ^SType^Sconditionicon ^SUnAlpha^N0.25 ^SShowTimerText^B ^SConditionDurEnabled^B ^SName^SNithramus,~`the~`All-Seer ^SOnlyInBags^B ^SConditionDur^N15 ^SCustomTex^S187616 ^SGUID^STMW:icon:1LmN4tIL5uof ^SEnabled^B ^SConditions^T ^N1^T ^SType^SITEMCD ^SOperator^S>= ^SLevel^N105 ^SName^SNithramus,~`the~`All-Seer ^t^Sn^N1 ^t^SDurationMax^N105 ^t^N73501^S~`~| ^Sicon^^

1. Import the string above on an empty icon.

2. Open the icon by right clicking.

3. Select the Conditions Tab on the lower part of the icon options.

4. Under the Item Cooldown tab, replace Nithrasus, the All-Seer with the name of your Legendary Ring.

Second Hidden Icon

^1^T^SShowTimer^B ^SCLEUEvents^T ^SSPELL_AURA_APPLIED^B ^t^SOnlyEquipped^B ^SType^Sitem ^SShowTimerText^B ^SName^SNithramus,~`the~`All-Seer ^SOnlyInBags^B ^SSourceUnit^Sraid~`1-40;~`party~`1-5;~`player ^SShowWhen^N1 ^SGUID^STMW:icon:1LmN4tIF3fhY ^SEnabled^B ^SFakeHidden^B ^t^N73501^S~`~| ^Sicon^^

1. Import the string above on an empty icon.

2. Open the icon by right clicking.

3. In the Choose Item(s) to Check tab, replace Nithrasus, the All-Seer with the name of your Legendary Ring.

Actual Icon displaying the info:

1. Select an empty icon where you want the info of the ring (buff duration and ring cooldown) to be shown.

2. Right Click it.

3. On the Icon Type dropdown menu, select Meta Icon.

4. Press the green +Add Icon button ONCE.

5. You must now see two "Choose and icon to check" dropdown menus

6. Clicking the first dropdown, you see a list of group icons.

7. Select the group containing the first hidden icon you imported.

8 Select the first hidden icon.

9. Repeat steps 6-8 for the second dropdown and the second hidden icon.



Congratulations, you now have a tellmewhen icon to show your legendary ring buff and cooldown!

For people concerned, i am the original poster on Curse as well.