Small HUD which shows the cooldowns on AMS, Mind Freeze, Strangulate, Raise Dead and Bone Shield.
Only shows up in Arena and BGs.
It also shows a Runic Power bar below, which can be untoggled without removing the CD tracking.
The rune bar above is https://wago.io/ZilzQDeVw and is not made by me.
This one always shows, also in non pvp scenarios.