Specifically these are from T1: Le dieu vivant. Frankly I've only skimmed the book so far, but wanted to add some long-overdue Comès content, since I'm not sure I got to him before.
Storywise, a wandering astronaut ("Ergün") is forced to land on a class-M planet, and Flash Gordon-like, has to deal with any number of strange peoples vying against each other. Then things go in to a sort of Conan the Barbarian direction, in which the hero is put to the physical test many times. Near the end there's also a stunning revelation that reminded me a bit of Planet of the Apes.
While the above might sound like Comès simply pastiched popular works of the day, in fact this was his very first GN, one in which he played the triple-role of writer, artist and colorist(!) Being from 1974 it's a bit dated, yes, but is quite impressive given the circumstances, and I'd say still holds up pretty well today as some classic BD 'pulp.'
Dieter / Didier Comès was born in 1942 in Sourbrodt, Belgiam, a small village in the east. His father spoke German and his mother Walloon & French, and he defined himself as a "bastard of two cultures", a characteristic of which we will find traces in his imagination. When he left school at 16, he worked as an industrial designer in a textile company in Verviers. At the same time, he learned about music. He was especially interested in jazz, trying his hand at percussion, and only came to comics later.
In 1969, he wrote Hermann, a gag strip published in Jeunesse du Soir. In 1973, Pilote published the first episode of "Ergun the Wanderer, The Living God." The second episode, "The Master of Darkness," would not appear until 1980 by Casterman. In 1975, the man already considered to be the spiritual heir of Hugo Pratt, wrote L'Ombre du Corbeau. It was in 1980 that Casterman published Silence, an album which established Comès reputation, and for which he abandoned color for the technique of black and white. Later came La Weasel (1983), Eva (1985), L'Arbre-Coeur (1988), Iris (1991) and La Maison Where Trees Dream (1995). Comès passed away in 2013. --Bedetheque & Johnny
(side note: why do I love skeletons so much?)
In Lambiek's entry I think one can see the Pratt influences:
https://www.lambiek.net/artists/c/comes.htm
Oh wow those shadows and lining are stunning.