The toughest Temtem to evolve is found very far in the game, and it’s one of the only Temtems (currently) that requires a special method to evolve. No, you won’t be able to level up Tuwai to make it into something new — you can’t trade to evolve them either.
Instead, you’ll have to complete a specific quest and interact with a unique stone. Later, Tuwai will evolve into different creatures, each with their own different type. For now, while the game is in Early Access on Steam, you’ll only have Tuvine to transform into.
More Temtem guides:
Simple Type Chart | All Type Strengths & Weaknesses | Which Starter Should I Pick? | Best Starter Guide | How To Breed Temtems | Eggs, Inheriting Values, Shinies & More
Tuwai is a colorful Toucan-like bird that can transform into a crystal-beaked bruiser called Tuvine. In Early Access, this is the most unique evolution method in the game. You can’t level him up — instead, you have to access a special area.
To evolve Tuwai into Tuvine, you need to bring Tuwai to the Crystal Shrine on Tucma. The Crystal Shrine is inaccessible until you complete the ‘Cultist Hunt’ side-quest, also found on Tucma.
On Tucma, travel to the far western island with the grapple-shot and talk to Valentina. She’ll give you the ‘Cultist Hunt’ quest. Travel to the far eastern island to find the Cult’s lair. There are four cultist battles here. Select Crystal-type Temtem to make the fights a whole lot easier.
If you don’t have any Crystal-type Temtem, check out the area in the southwest corner of the main island — you can catch some Shuine or Bunbun Temtem there. Both are Crystal type, and they make clearing the cultists more manageable.
After defeating all four cultist battles, go to the Crystal Shrine and step to the place of power with Tuwai in your #1 slot. Now your previously-cute Toucan will become a diamond-encrusted super-bird.
Taking a look at the Temdex, it’s pretty clear that there (might) be multiple evolutions for Tuwai — kind of like Eevee. Perhaps there will be multiple nature shrines, and depending on which you choose, you’ll get a different Tuwai evolution? That speculation might be way, way off, but here’s hoping Temtem takes a few more of Pokémon’s best ideas.