The Pokémon community has only gotten more and more creative in how they artificially add difficulty to their runs through various titles over the years, whether that be implementing perma-death and catching restrictions, Shiny-only playthroughs, or any other odd rule implementation you could think of.
Outside of the typical Nuzlockes, monotype playthroughs are among the most commonly seen types of restricted Pokémon runs. This ruleset only allows for players to use Pokémon that feature a specific typing or will once fully evolved, along with whatever other additional rules the player wants to add on.
What fans don’t typically see is one player deciding to complete an entire playthrough using a team composed of only one specific species of Pokémon. But that is exactly what former Pokémon VGC World Champion Sejun Park did, as he used six Pachirisu to take down every obstacle in his path and become the Sinnoh League Champion.
Sejun has a long and storied history with the pure Electric-type Pachirisu, dating back to before his 2014 Worlds run, where he used Pachirisu as a sort of anti-meta tank in his team because he predicted that no one would expect the little squirrel to be present at the event.
His gamble paid off, with Pachirisu often disrupting his opponent’s strategies with its unconventional presence and use of Follow Me, a move that redirects attacks away from allies and towards itself. This allowed Sejun to use the Electric Squirrel’s deceptive defenses, which allowed it to live more hits than many players expected, to take the heat off of his more critical team members.
He had to use a similar strategy when going through Brilliant Diamond and Shining Pearl only using Pachirisu, as it has a limited movepool, lower than average stats in most areas, and is a poor matchup against many of the late game obstacles presented in Sinnoh—including Cynthia’s monster of a Garchomp.
Not only did Sejun beat the game using a team of the same, yet still relatively diverse, electric rodents, but he did so without going out of his way to grind or using non-Held Items in battle. In his own words, the combination of those added rules along with using only Pachirisu led to one of the most challenging and “hardcore” run he has ever attempted.
From picking up the game at launch to beating Cynthia, Sejun completed his Pachirisu-only run in under four days, streaming the entire thing to an audience of over 800 viewers according to Twitchmetrics.
Now that BDSP has been out for more than a handful of days, you can expect to see more challenge runs start popping up across all platforms, but none can say they were the first to complete the game just using Pachirisu, nor would many players want to put in the time to do so.