0248 Tyranitar

Smack Down tends to be a stronger option than Bite due to superior energy generation, which is notable due to Tyranitar's costly charge moves. However, the latter lets Tyranitar become a Ghost- and Psychic-shredding machine. Iron Tail is a poor move. 

Brutal Swing costs the least energy and benefits from STAB. Crunch is slightly more expensive and is therefore the less preferable option, but it can occasionally provide Defense drops. Stone Edge is powerful and provides good coverage, but costs quite a lot of energy to use. Fire Blast demands too much energy to be consistently worthwhile. 

Tyranitar’s heavily attack-weighted stat distribution does it no favors down in Great League. A double weakness to Fighting-type damage, in addition to weaknesses against common Water, Grass, and Ground-type attacks, makes it a very risky Pokemon. While it shines in certain limited metagames, its stats combined with the fact that a lot of other things can do its job don't leave it super happy.

The higher CP cap in Ultra allows Tyranitar to perform better, though not necessarily well. Its Rock/Dark typing gives it a solid matchup against both Giratina forms, but make it much weaker against Fighting-types, in addition to Grass and Water Starter Pokemon.

Tyranitar's not bad, it's just poorly positioned. It's got stats, it's got moves, it's just...it doesn't beat much? It simply suffers from having too many weaknesses, especially its double weakness to Fighting. While incredibly powerful against Mewtwo and the Giratinas, it fails to handle the top Dragons in the format, and it stands no chance against powerful Waters like Kyogre. It's good against, like, Lugia, at least? That's something?

Shadow Tyranitar is preferred over its regular variant due to the consistency of its Fast Attack pressure. Smack Down is generally preferred due to the ubiquity of Zacian and Flying-type Pokemon, but Bite offers greater pressure against Groudon and Dialga.