Ttar useful for gen4?
Will it be outclassed?
Answers
In short: No
In long: Tyranitar will be the undisputed king of gen IV, matching the lake trio, Giranita and Cresselia, and great neutral DPS against Regigias (as its boosted by partly cloudy as is Tyranitar's rock set). No dark type in gen IV poses any threat to Tyanitar, all being glass cannons, unable to compete with Tyranitar's bulky/DPS combo. Togekiss is likely to be a gym defender for its double fighting resistance that tyrantiar matches with smack down, and matching numerous anti-machamp gym defenders with either of its sets.And thats just the legendaries and defneders, as a raid attacker, it 's a beast even if hitting neutral. While Ryperior might compete with it for the rock DPS throne, Tyranitar will still (stone)edge out a head agaisnt ice types because Rhyperior's weakness to ice
I know this is far into the future, but it will also match Reshiram and Kyogre, as well as thunderus and Tornadus in gen IV with just its rockset
In a way that almost makes it more baffling. He's expressed hesitation about using Tyranitar against Regice due to Regice packing SE fighting and ground type moves, despite Regice's lackluster attack stat. He had similar concerns about using Kyogre against Zap Cannon Regirock. Him recommending Tyranitar against Regigigas doesn't match considering there's a pretty good possibility of it getting Rock Smash/Focus Blast, only this time coming off an attack stat capable of laying down the hurt without STAB.
As dark, no. Darkrai could be better, but is mythical so no one is going to have more than 1 and it might not become available until much later. Weavile and Honchkrow can both get slightly better DPS with optimal movesets but Tyranitar is so much tankier it'll still be the dark king.
As rock, possibly. Rampardos with any rock moveset will be the king of rock DPS by a large margin and Rhyperior with SD/RS would out-DPS and out-TDO Tyranitar.