Victini

Victini's V-create is one of the strongest attacks in the game, being able to 2HKO many common physical walls such as Landorus-T, Gliscor and Reuniclus and Fire-resistant foes such as Latios, Keldeo, Garchomp, Rotom-W, and Gastrodon. It also OHKOes virtually any neutral offensive target, making switching into it a very difficult prospect. Moreover, Victini's access to Bolt Strike and Brick Break means that many of its checks like Tyranitar, Politoed and Heatran need to be careful switching in. Victini's access to U-turn also means it can safely maintain momentum for its team and thwart Tyranitar's attempts to come in and Pursuit trap it. These traits make Victini a decent wallbreaker on offensive teams.

However, Victini isn't seen too often due to its awful defensive typing making it difficult for it to switch in safety. It can only directly switch into Alakazam lacking Shadow Ball and Calm Mind Reuniclus variants with Psychic + Focus Blast and is often forced out by faster threats such as Latios, Keldeo, Garchomp and Terrakion. The presence of sand and rain is also particularly problematic, as the former cuts into Victini's already limited longevity with its vulnerability to Stealth Rock, while the latter weakens Victini's V-create. Finally, Victini has to be very careful about spamming V-create to avoid letting Tyranitar and Heatran switch in and take advantage of it. As such, it's often passed over for other wallbreakers like Dragonite, Scizor, and Terrakion since they all have better defensive utility. As an offensive Fire-type, Heatran and Volcarona are often superior, as the former has better defensive utility while the latter has access to Quiver Dance and a much better matchup against sand teams. Both also have the benefits of being far less prediction reliant for damage and not being as vulnerable to being Pursuit trapped by Tyranitar.