The official Wordpress theme powering https://seshan.xyz/ (My website!)
This is a pretty barebones Wordpress theme using the Materialize CSS framework. Why? Well after a couple of attempts to replace the old Classic ASP+Random HTML5 Theme that ran my old website, I ended up settling on Wordpress as a backend because I'm lazy. It ended up working pretty well, though!
Sure! The theme is AGPLv3 Licensed, so you are free to fork and modify as you please! Just follow the terms of the license, which more or less boil down to you must continue to redistribute your modified work under the AGPLv3 or later, and provide the source code (unlike the normal GPL, the AGPL requires you to make sources available for network services aswell).
You'll definitely want to fork though, there is still a lot of hardcoded text, images, etc, that you'll need to change yourself.
Also, don't expect this to be a great Wordpress theme either. My website is fairly simplistic, so I can't promise this theme will work correctly or at all for sites that need more than a blog and some pages.