Pokémon UNITE Crustle and their build path has a few key moves and held items that will give you the edge on your opponents.
Pokémon UNITE Crustle Build
Crustle happens to be the best tank in Pokémon UNITE at the moment, according to Pokemonunite.gg's tier list. Fury Cutter and X-Scissor provide Crustle with a lot of damage for a tank, as well as the utility that comes from Rock Tomb and his UNITE skill, Rubble Rouser.
Fury Cutter will want to be the first move you pick up. Fury Cutter allows for quick clears on Wild Pokémon, helping you level up from Dwebble into the mighty Crustle. Each hit on Fury Cutter buffs up the last, meaning by the time it's your fourth or fifth hit, you will big be doing big damage to either Wild Pokémon or other players.
After Furry Cutter, prioritize Rock Tomb and X-Scissor, as those as your other strongest moves.
Assault Vest, Rocky Helmet, and Aeos Cookie are Crustle's strongest held items at the moment. Assault Vest and Aeos Cookie compliment Crustle's tankiness, while Rocky Helmet will get a lot of value as you will be taking a lot of hits from players.
Rocky Helmet is particularly good here since Crustle has a lot of shields. The item will deal percent damage to nearby opponents based on how much damage you take, whether shield or health damage.
For your item, you want to take Eject Button to quickly teleport around the map to score points from dunking or set up plays for your team.