If held by a Tyranitar, allows it to Mega Evolve into Mega Tyranitar if its Trainer has a Key Stone. Each Trainer can only Mega Evolve one Pokémon per battle.
Unaffected by item negating effects (such as Embargo and Klutz). Item manipulating effects (such as Trick and Fling) cannot give Tyranitar a Tyranitarite or remove a Tyranitarite from Tyranitar.
Outside of battle
If held by a Tyranitar, allows it to Mega Evolve into Mega Tyranitar when it performs a Spectacular Talent during a Pokémon Contest Spectacular while its Trainer has a Key Stone. Tyranitar will remain a Mega Tyranitar until the Talent Round ends.
The player can obtain the Tyranitarite by defeating Mega Tyranitar in Stage 420 found on Blau Salon.
The Tyranitarite was also available as a prize during the Mega Tyranitar Competitive Stage. This Competitive Stage ran on both the Nintendo 3DS and Mobile versions from July 25 to August 1, 2017.
The Tyranitarite enables the following Mega Evolutions:
Erases Pokémon and disruptions around three spots you tap. Erases five tiles in a + shape surrounding each spot. Does not activate if the foe is defeated. Only gives 3 seconds to tap. Can erase fewer than 3. The disruption countdown formerly did not decrease if this effect was triggered by the first match of the combo, but this was corrected in Version 1.3.28 (3DS)/1.9.1 (Mobile).