Jirachi

Jirachi is an extremely versatile Pokemon thanks to its great stats, movepool, and typing. As a Calm Mind sweeper, it distinguishes itself from Suicune and Celebi by virtue of its part-Steel typing, which grants it immunity to passive damage from sand and Toxic and enables it to take advantage of Choice Band users such as Salamence, Aerodactyl, and Tyranitar locked into their STAB attack more easily. Furthermore, Jirachi's colorful array of coverage moves makes it difficult to handle defensively, and its access to Wish can invalidate special sponges such as Blissey as answers while enhancing Jirachi's defensive capabilities. Jirachi also has some niche options at its disposal and can run physical sets to lure out and eliminate Pokemon that typically scare it out such as Tyranitar and Snorlax.

On the other hand, Jirachi is held back by a very exploitable weakness to Earthquake, which makes it prone to being trapped and taken down by Dugtrio and allows metagame staples such as Tyranitar, Metagross, Swampert, Salamence, and Snorlax to potentially scare it off. While Jirachi has the needed coverage and support options to threaten all of these, it cannot fit each into a single set and thus will remain kept in check by some popular Pokemon.