I like the idea of rolling release in theory, but stability is extremely important to me because I use Linux as my daily driver.
EndeavourOS and Manjaro aren’t really going to do much to address your desire to use terminal more than Mint IMO, either; most mainstream distros like that emphasize usability first and foremost.
If you’re looking to really get under the hood, go with Arch ans follow a guide so you don’t bork anything too badly. Arch uses a different package manager than Mint/Ubuntu, so some of the commands might look different if you’re not following Arch-specific guides, but terminal is terminal is terminal in many cases. You can run Steam on Arch, and building the core functionality on your own will get you acquainted with terminal.
Although I’ve used everything from Arch to Zorin, and eventually you will have to use terminal for something. Just depends on what your longterm goals are, what usability you will need to rely on quickly, and how you think you’ll get to those goals most efficiently.
Is this just SMTV: Royal? Like basically the same game but with some added content?