Stolen Realm

Stolen Realm is a fantasy tactics game where you'll start as a single class (for instance, Warrior, focusing on Might for damage and Armor to shrug off incoming attacks) and quickly evolve into an insane multi-class godlike creature (the Warrior is now also a Monk, rapidly moving about and throwing enemies into one another, but also a Thief who steals enemy actions and backstabs for criticals!) The equipment and "fate" systems allow you further angles to develop your own unique play style as you progress your campaign. There's also the pure roguelike mode that speeds up progression considerably while dropping out the between-dungeon segments done in town during the main campaign (those segments are fun for the campaign though, as your progression really shines there!) Co-Op is done with simultaneous player turns followed by all enemies, permitting ridiculous schenanigans with your friends. And if you're the type that doesn't have friends, you can play as many characters per human as you want up until the party cap is filled, though it really helps to spread the mental load amongst people or just run 2-4 characters. When playing as a duo (most of my playtime), we each run two characters and that grants everyone plenty of fun synergies and things to do without getting TOO crazy!