Wait how much does this manga actually cover for F/GO?
I'm an anime-only and have no real knowledge about what happens after Ritsukia and Mash encounter with the reality that's an alternate of the Stay Night (Medusia lancer, Cu Chulainn caster) up to the Camelot films and Babylonia
-mortalis:stella- is one of two manga that focuses on the plotline of Fate/Grand Order, the other being -turas réalta-. Both cover Singularity F and the first singularity Orleans (though have their own interpretations on each). However, after that, they cover different chapters of the story. This one covers the second, fourth, and sixth singularities (Septem, London, and Camelot), while -turas réalta- covers the third, fifth, and seventh singularities (Okeanos, America, and Babylonia). They're not on here, but the first three volumes of -mortalis:stella- have an official translation.