in case you're wondering why the classic game dev advice is always "make and release a bunch of small projects first before jumping into a big one" this is why
true fact back in 2012 when I visited valve they gave me a "all past and future valve games for free" code and since then the only new paid game they released was Artifact
If your final boss has 2 forms: the final form should be the hardest form
if your final boss has 3 or more forms: the final form should be the easiest form