
The best moveset for Tyranitar in the current competitive meta typically features the moves Rock Slide, Protect, Knock Off, Low Kick.
In the Pokémon Champions meta, Tyranitar can be countered by exploiting its weaknesses (fighting 4x, bug 2x, fairy 2x, grass 2x, ground 2x, steel 2x, water 2x) and using effective check/counter teams.
The best item for Tyranitar is typically Tyranitarite, based on high-level tournament and ladder stats.