I love Monster Sanctuary for this reason! It's Pokemon with skill trees for every 'mon and a metroidvania-style overworld.
The monsters you capture operate in teams of three and you can have multiple teams on the back burner, all with their own unique build. Maximizing your damage requires synergizing your team's skills—which you have to handpick as your 'mon levels, of course—but you can also just experiment to find silly or busted builds.