Thanks for your support, I will refer to this patch in mod description then.

I agree this patch is too complicated.　It is not a bad idea separating this patch. If you want, I will maintain this patch as possible. (In fact, whether separate or not, I will make and maintain Japanese version of this patch.)

I would include this patch but things like events are too complicated for me(I am noob at modding) to include in the mod and maintain/update mod when needed but if you don't mind maintaining/updating this patch I will refer to this patch in mod description instead.

Don't mind.
Probably this will work as expected, i.e., Lowee's ruler is Blanc (or Rom/Ram), for example. The portrait and its name is proper ones.
But to do this, I had to change most of species files (and add hidden event to change initial ruler's portrait/name at game startup). I wonder you might not like this change. You are free to merge this patch or not. If you want to change names, you can edit speceis_names file and localisation file.
Note: Some empire which ruler should be elected would change initial ruler and as the result its portrait mismatch the empire name. This is regular action, not bug, I think.

Sorry for late reply, I was busy. I am confused, is it working properly now?

Probably I succeeded.

It does not work... After many modifications I can barely arrange the country name and the species portrait, but can't ruler portrait. It might be that the ruler portrait could not control in AI countries, although it is enabled in player country. Finding another way.

Let me know if it works, I will update it then.

@furkanmeral7
It seems using same key both in portraits group definition and in species_names definition will arrange the ruler-portrait and country name, i.e, ruler = Purple Heart & contry= Planeptune. Anyway I will try.

@furkanmeral7
It seems named randomly, I think. I want to name, for example, "Lowee" for Blan's empire, but I could not find the way. My patch is a bit better way than nameless.

Hi, I never experienced nameless AI empire but I guess its because I always use my own created empires and always force AI to use them too. Thanks for this, btw. But I have a question. Do they get these names randomly? Because if they do its gonna be weird for example when iris heart's home planet is named Lastation.