Tyranitar can effectively utilize both an Adamant Nature and a Jolly Nature depending on the set, so it normally would not matter. However, because the Jolly Tyranitar has better IVs, you should choose this one and build a team around it. Jolly Tyranitar has two popular sets- Choice Scarf and Dragon Dance.
Tyranitar @ Choice Scarf
Ability: Sand Stream
EVs: 252 Atk / 4 Def / 252 Spe
Jolly Nature
- Stone Edge
- Pursuit
- Superpower
- Crunch
Choice Scarf Tyranitar is a popular choice for teams which enjoy having threats such as the Lati Twins and Gengar removed. It reaches 364 Speed at Level 100, meaning it can outspeed these Pokemon and easily KO them without taking damage. It also has proficient revenge killing capabilities as it can trap weakened Pokemon with Pursuit.
Tyranitar @ Tyranitarite
Ability: Sand Stream
EVs: 252 Atk / 4 Def / 252 Spe
Jolly Nature
- Dragon Dance
- Stone Edge
- Ice Punch
- Superpower
Mega Tyranitar is a better choice for a Dragon Dance set than Tyranitar as it reaches an important Speed tier that regular Tyranitar does not. After one Dragon Dance it can easily outspeed and deal huge damage to most Pokemon with the appropriate coverage move.
