There is a large amount of build customization you can do with your party in Clair Obscur: Expedition 33, experimenting with Weapons, Skills, Pictos, and ...
There are various ways of getting gear, but outside of raiding, exchanging your hard earned Tomestones if the best.
Looking for Tomo's cat seems easy, but thanks to the Goblin King, it becomes more complex, so here's a step-by-step guide to finding it in The Forge.