Tyranitar gained a few tricks with the addition of Z-Moves. Here's one of my favourites:
Tyranitar @ Ghostium Z
Ability: Sand Stream
EVs: 252 HP, 252 Attack, 4 Def
Brave nature (Speed IV 0 or 1)
- Rock Slide
- Crunch
- Curse
- Protect
Z-Curse Tyranitar for Trick Room in doubles. With a Brave nature and a low Speed IV, Tyranitar becomes slower than minimum speed base 40s after a single Curse (speed tying with minimum speed Gastrodon), and slower than minimum speed base 30s after two. With Curse boosting its physical defence, Sandstorm boosting its special defence, and maximum HP investment boosting its HP, Z-Curse Tyranitar becomes bulky enough to take most super effective hits without much worry, as long as they're not Fighting hits. Z-Curse gives Tyranitar +2 attack as well, making it like a Swords Dance in power boost, and at +2 Tyranitar hits very hard. Crunch usually KOs most things that don't resist it, and Rock Slide brings a lot of foes into yellow health in one go, hits both opponents, and causes flinching. It has its weaknesses and you need some team members that can eliminate fighting types, but overall it's a very scary powerhouse under Trick Room conditions that isn't that easy to deal with. It is so bulky that it can't be easily revenge killed or eliminated even if an enemy goes first with a super effective hit, yet it still has the power of a Swords Dance sweeper with a 134 base attack stat. Under Trick Room this Tyranitar essentially has everything in raw numbers. Bulk, ability to move first most of the time, and offensive might, and most pokémon only get two of those three.
There are different Trick Room setters you can consider:
Stakataka loves Sandstorm being up, has very low speed, can support with more Rock Slide to ramp up flinching even more, and can even Skill Swap to reset weather and give Tyranitar Beast Boost for a bit of overkill as this Tyranitar Beast Boosts on its Attack stat. It does share several weaknesses with Tyranitar however, notably Water, Ground, and Fighting.
Oranguru is always a solid Trick Room setter, and this is no exception. Oranguru can threaten fighting types and offer Instruct support to Tyranitar to make it even more dangerous.
Reuniclus is very slow, bulky, immune to Sandstorm, and eliminates fighting types with ease. Reuniclus can also use After You which is beneficial under Trick Room conditions with its low speed, especially when you have other members in your team that aren't as slow.
Claydol is immune to Sandstorm, eliminates fighting types with Psychic attacks and Rock and Steel types with Earth Power, is immune to Ground, and can Skill Swap to reset weather and give Levitate to Tyranitar. However its stats are a bit subpar otherwise, and it's quite fast for Trick Room.
Mimikyu is one of the most reliable setters with its Disguise and Fake Out immunity, it can also Psych Up Tyranitar to get its own boost, and eliminates Fighting types with Play Rough. However, it's very fast for Trick Room.
Super Size Gourgeist has reasonable bulk, is immune to Fake Out, can threaten water types, and gets Trick-or-Treat. Trick-or-Treat can be used on Tyranitar to give it an immunity to Fighting (use it after Tyranitar sets up, because Curse can't be used as a setup move once Tyranitar gains the Ghost-type), and also on bulky opponents to make them weak to Tyranitar's Crunch. Gourgeist should ideally hold an item to slow it down so it's slower than Tyranitar for that combo. I'll have to give
credit to Serebii for inspiration on the Gourgeist idea, although he didn't use it with Curse.
Eviolite Dusclops has a lot of bulk, is immune to Fake Out, can Frisk the enemy team, and gets Bulldoze. Run Tyranitar with a Weakness Policy over Ghostium Z for this combo, as it allows Tyranitar to go to +3, and Tyranitar at +3 is even scarier than at +2. Ideally you'd set up Curse while setting up Trick Room to reduce the damage Tyranitar takes from Bulldoze, at +1 Defence with a -Atk nature on Dusclops and a 0 Attack IV, Dusclops's Bulldoze only deals 12-16 damage to Tyranitar (out of its 207 HP) and triggers the Weakness Policy.