Evolution is a simple concept in Pokémon but there are some species like Basculegion that quickly complicate the formula by implementing hyper-specific conditions only achievable with one type of Basculin—making it a grindin Pokémon Scarlet and Violet’s The Teal Mask DLC.
To get a Basculegion, you need to catch a specific Basculin, which is only obtainable through the DLC map of Kitakami. You also have to make a play on the Big Fish Pokémon’s lore, which says it is “possessed by the souls of other Basculin in its school who did not survive their harsh journey swimming upstream,” to make it evolve.
What Basculin can evolve into Basculegion in Pokémon Scarlet and Violet The Teal Mask?
Only one of the three different Basculin forms is capable of evolving into Basculegion in any game, and that is the White-Striped Basculin that were first found in the Hisui region and Pokémon Legends: Arceus. Both the Blue and Red-Striped forms do not evolve at all.
There are also two forms of Basculegion available to you, a male and female variant. The male form is the Water/Ghost type you are likely familiar with because it has striking pink accents and was a mount in PLA, while the female variant has a more relaxed expression and white-centric color scheme.
How to evolve Basculin into Basculegion in Pokémon Scarlet and Violet The Teal Mask
Once you catch a White-Striped Basculin, get ready for a bit of grind because you need to nearly have your Basculin make itself faint in battle to trigger an evolution.
To evolve, you need to have your Basculin deal over 294 damage to itself using moves with recoil like Wave Crash, Head Smash, or Double Edge. You also have to do this without letting it faint at all or that counter will reset back to zero—though you can heal that damage off between battles with no consequences.
Since Basculin is very strong but also frail, I just went around the Timeless Woods and used Head Smash on the local Spinarak population until I racked up the right amount of recoil. That made it easy to avoid being knocked out since I could one-shot the Bug/Poison-type while not risking a heavy hit in return if I missed an attack.
After you think you have taken enough recoil damage, you will need to level up your Basculin and cross your fingers that it evolves. This is one of the most specific evolutions in all of Pokémon, but there are plenty of other odd species like Ogerpon featured in this specific DLC adventure.
