The best matching shirt to go with our Order Hall Class set Shattered Abyss is Wraps of the Blood-Soaked Brawler, however if you did not get it during its time most of us just assumed it was unobtainable. However the shirt is still available it just requires some grinding.
1. Go to Orgrimmar and zone into Brawler's Guild (lots of guides out there if you dont know where it is)
2. Talk to Tiana Nevermorn and buy [Bag of Chipped Dice]
3. Go to talk to any Brawl'gar Arena Grunt and <Present the Bag of Chipped Dice.>
4. Talk to same NPC again and "I want to fight a random enemy!
5. Type /script AddTrackedAchievement("9177")
6. Repeat step 4 until you have killed every boss on that list.
The last part could very well take you hours and hours.
Once you are done and get the achievement the shirt will be in the mail, and thats when you'll realize you just wasted 10 hours of your life for a fucking shirt.