Well I'm sorry but that assumption is incorrect. Here is the process to start playing:
A little over a year ago an email was sent to every person who had pledged. It had a Game key in it to use in creating a game account. A Forum account is not sufficient to get into the game.
Those emails didn't always reach the people they were sent to, and often they wound up in Spam folders due to ISPs making bad choices. So your first thing to do is look in your spam folder for an email from VR. If you don't find it - many spam folders get emptied automatically - then you need to put in a ticket to Support telling them your situation and asking them to resend the email.
The email has detailed instructions on how to create the accounts you need to get into the game. When you get it, read everything, and follow exactly. I emphasize this because many players get delayed because they skim thru and wind up in the support forums asking questions that the email already answered LoL.
If you have any trouble with the process that the email describes, please post in the Support Channel and you'll get some help.
See ya on Terminus
I've managed to get the standalone patcher to work on linux. It needs winetricks dotnet472.
umu-launcher is basically Steam/Valve's entire containerized proton launch mechanism made to be used outside of steam on linux. It's already the default backend used for Lutris and Heroic for non-steam games:
https://github.com/open-wine-components/umu-launcher
Full setup:
Using umu-launcher and GE-Proton:
WINEPREFIX=~/Games/pantheon PROTONPATH=GE-Proton umu-run PantheonSetup_184.exe
WINEPREFIX=~/Games/pantheon PROTONPATH=GE-Proton umu-run winetricks dotnet472
WINEPREFIX=~/Games/pantheon PROTONPATH=GE-Proton umu-run ~/Games/pantheon/drive_c/users/steamuser/My\ Documents/My\ Games/Pantheon/PantheonLauncher.exe
ENJOY