Hmm, Kate has a feature called “Sessions”, which might be able to do that.
You can create just one session and then in the settings, set it to always load that session:
Well, and there are those two checkboxes, which I’ve also marked. The “Newly-created unsaved files” sounds like what you want, but seems to be broken on my system. It just reopens an empty file for me. Is that also broken for you?
Apparently, it’s like Smash Bros in the Ubisoft universe, except it’s a first-person shooter.
So, you got different factions from Far Cry, Splinter Cell etc. with which you can play…