Unlike most games, evolution in Pokémon Legends: Arceus doesn’t happen automatically. You need to meet certain requirements and evolve them manually in your satchel’s menu. Hisuian Qwilfish, a Dark/Poison regional variant, is no different.
To evolve your Hisuian Qwilfish into Overqwil, you need to use Barb Barrage 20 times in Strong Style. Quilfish automatically learns this move at level 16. You can unlock the move's Strong Style if you use Barb Barrage in battle and level up until it's mastered.
Related: How to evolve Ursaring into Ursaluna in Pokémon Legends: Arceus
Overqwil’s barbs aren’t for show—this Pokémon has a fairly high Atk stat and decent HP, Def, and Spd. If you're raising effort levels, make sure that its Atk is at least maxed out. Just be careful: its Sp Def is fairly low, so try to avoid Pokémon that specialize in special attacks like Voltorb.
Overqwil is resilient to four types: Grass, Poison, Ghost, and Dark. But another good thing about it is how it’s only vulnerable to one: Ground. As long as you avoid fighting Pokémon like Garchomp and Ursaluna, Overqwil will perform well in battles.
For more help with Pokémon Legends: Arceus, we at Pro Game Guides have you covered.
Bianca Versoza is Pro Game Guides' Weekend Editor. With over three years of experience in gaming journalism, she specializes in anything remotely turn-based and strategic, like Pokémon, Valkyria, and Honkai: Star Rail. Bianca is a huge fan of Square Enix, RPGs, party games, and visual novels, but will play anything with a banger OST. She's a proud early bird.