Tyranitar

Tyranitar has a formidable base stat total and pervasive STAB coverage, and has long been a staple Pokemon for players since its release. To begin with, it was best utilized as a Dark Type attacker, where it was the absolute top pick, but once it gained Smack Down via its own community day, it became the top Rock Type attacker as well. The times have changed and Tyranitar lost its "best" title in both types, But in June 2023 the winds of change blew in Tyranitar's favor once again as it was given access to Brutal Swing. With this, Tyranitar towers over much of its competition as a Dark Type, and has long since returned to its glory days as a Dark Type juggernaut. 

Best PvE Offensive Moveset

• Bite is best paired with Brutal Swing, while Smack Down* should be paired with Stone Edge.
• Iron Tail is okay against Pokemon weak to Steel but not Rock, but its use cases are narrow.
• Crunch is okay, but definitely inferior
• Fire Blast is underwhelming in every aspect.

Best PvE Defensive Moveset

• Iron Tail edges out Smack Down due to not being resisted by Fighting.
• Bite barely tickles attackers and is resisted by Fighting to boot.
• Tyranitar faints quickly vs. Fighting-types and needs Crunch to threaten damage.
• Brutal Swing is okay too, but it is slower on defense.
• That said, Stone Edge has a very early damage window.
• Fire Blast is underwhelming in every aspect.

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.