It is the first time being talking about Clip Studio Paint @acidyo . Thanks for pointing.
I have Krita 4.2.1 installed on Kubuntu since by default it is predisposed for KDE and it works quite well. Of course, it consumes a lot of RAM.
It is based on the KDE platform libraries and included in the Calligra Suite (formerly known as KOffice).
The advantage of Krita is that it is a free, professional program of digital painting made with free code.
Regards.