Siralim Ultimate maybe? The Steam description: "Siralim Ultimate is a monster catching, dungeon crawling RPG with a ridiculous amount of depth. Summon over 1200 different creatures and travel through randomly generated dungeons to acquire resources, new creatures, and loot."

At some points, you need to rethink your setup and incorporate the new stuff you've found along the way to be able to mindlessly grind on but I've played for 160 hours so far and having a blast trying different strategies. Evoker is my favorite class so far - casting so many spells before the battle even begins that the enemy never gets their turn.