I was so tempted to go with an Assault Vest T-Tar because it's so good, but I'm pretty sure those are running rampant through OU tier at present. I dunno how common this set is, though... hopefully not very.
Tyranitar @ Leftovers/Tyranitarite
Sand Stream
Adamant
252 HP/Def, 252 Att, 4 HP/Def
- Pursuit
- Stealth Rock
- Toxic/Thunder Wave
- Stone Edge
The point behind this set is to punish the opponent for switching out as much as you can. Stone Edge acts as T-Tar's primary STAB, and Stealth Rock sets up a hazard to harm the foe for switching. You can choose between Toxic or Thunder Wave for status to ensure the opponent has an incentive for switching, and Pursuit is to further punish them for doing so. The item this guy holds really depends on which you feel is more important: self-healing or better stats overall, and personally I'd go for the Mega-evolution, since Mega T-Tar does pretty much the exact same things as regular T-Tar could. For EVs, I'd probably go with Defense over HP, or some sort of balance between the two, since its SpDef is already going to be massive enough with Sand boosting it.
There are three things off the top of my head that this set will have trouble with: Mega Absol, Conkeldurr, and Lucario. Mega Absol resists Pursuit and bounces back your Rocks and status effect, leaving you having to hope you can hit it with Stone Edge. Thankfully, even regular T-Tar should be able to handle a Play Rough and OHKO Mega Absol with Stone Edge so long as said Absol has no defensive EVs. Conkeldurr and Lucario, however, will pretty much force you to switch out; not only do they resist Stealth Rock and both your STABs, but Conkeldurr thrives off of being hit by Toxic thanks to its Guts ability, ensuring that if you run this set, you'll need a Conkeldurr counter. Furthermore, Lucario isn't hit by Sand damage and a special variant could likely come in when your sandstorm tapers off and crush you with an Aura Sphere. In fact just about any Fighting type would be difficult to handle, but those two in particular come to mind, so a strong Psychic, Flying, or Ghost type would be a good idea to carry to help handle them.