I've 3,3k T-tar 12/15/14 and I don't know if it's worth to power up. I've also 15/10/14 Larvitar whose I can evolve. What should I do with it? Is PC/SB Mewtwo better vs psychic type than B/C T-tar?
PC/SB Mewtwo has better DPS against psychic than B/C Ttar but it's much harder to get candy for it.
It can be worth powering up B/C Tyranitar if you want to do solos against Alakazam/Gengar/Jynx etc. in the future or if you frequently do EX raids and want to boost your team. It's obviously also good for murdering any psychic types in gyms.
It's a good investment for future, but it's not the most useful mon in the game currently. Great specialist, far from the best generalist.
Dark type tyranitar is actually far more useful than rock tyranitar in the current meta, given the lack of rock weak raid bosses/gym defenders, lack of good dark types aside from Tyranitar, and also the fact that Dark tyranitar will actually outclass rock tyranitar thoughout all of gen IV, rock Tyranitar's use will only come into viability when the Taio Trio come out in gen V, (unless rotom's alternate forms are raid bosses, where rock will be good agaisnt Frost Fan and Heat)
Also given that in gen V, Gigalith may actually usurp Rock Tyranitar's throne, given it's higher Attack, higher defense (slightly lower Hp) if Gigalith gets Smack down or another rock fast move and a 2 bar charge rock move, it will make smack down tyranitar utterly outclasses against all but 1 pokemon, gen VI's Yveltal
Darkrai is a a lot more frail that Tyranitar, even bofore the 9% nerf, it wont be able to compare unless it get snarl/foul play or soemthing, their comparable attack before the nerf will only push tyranitar up more.
Rampardos may be strong in damage, but its frail the main draw about why tyranitar is so good is its impressive bulk for its high DPS, ram will lhave sky high DPS, but its the machamp of rock types, it folds very easily, Tyranitar has that impessive bulk to last
(but Gigalith has better bulk, and the added use of being able to counter bug types withoutbeing weak to them)
Darkrai won't get a 9% nerf, as it's not as OP as Mewtwo or the weather trio. It would therefore be a better DPS option, but glassier, than Tyranitar.
Rampardos will indeed be used as a glass canon (unlike Machamp, who sports 50 more defence and only 10 less stamina and is therefore way more bulky) and I don't know why you even mention Gigalith who has an attack stat slightly higher than Rhydon. It must have something to do with you liking Aggron, (relatively) low dps and high survivability seems to be your thing.
