It looks like Warzone was made from scratch (HTML, CSS, Javascript, Unity, Flash, etcetera), but it is a non-static website.

Things like Github and repl.it can only make static websites.

I have been looking for a static website hosting service that allows you to program the site from scratch (that can also contain PHP and MySQL).

So what did Fizzer use to make Warlight?

Linode according to https://www.warzone.com/Forum/311197-warzone-new-home.
Technically, you could set up your own web servers but you’d have to make them secure, etc.
A free* web hosting service that meats your requirements is https://000webhost.com. *=pay monthly for databases.

Unsure if money is an issue for you, but if not I'd definitely recommend linode. Warzone has only been hosted by them for a very short period of time, but I've rented one of their VPS's for close to a decade and had a fantastic experience with them. Over 99.99% uptime, fast to answer any questions I've had or fix problems that came up.