It will take a little work to get Hisuian Qwilfish to evolve in Pokemon Legends: Arceus. This title brought not only new Pokémon, but also unique evolutionary methods.
Most Hisuian variants have special requirements that must be met to evolve, rather than simply grabbing an item or reaching a certain level. As for Hisuian Qwilfish, trainers would definitely need to do some research if they wanted to evolve into Overqwil.
The second generation Pokemon with a special new evolution
In order to develop Hisuian Qwilfish into Overqwil, trainers will need to use the Strong Style version of the Barb Barrage movement about 20 times.
Fortunately, Qwilfish must go through this moment when they are caught. The Qwilfish learns that Barb Barrage is at level 15. The closest a trainer can get to catching a Qwilfish, though, is by surfing the coastal cobalt lands. He will be in his mid-20s at this point in the game.
This is also a very easy requirement to fulfill since trainers may want to spam strong, powerful archers anyway. This move has only 60 core strength, which wouldn’t be enough to KO any low-level Tangela save. Oftentimes, a Hisuian Qwilfish will need extra strength from Strong Style to cause meaningful damage from Barb Barrage.