These picture set is about 20 years old, about 1996-1998. The website / artist was (if I recall it correctly) Sirius Secret Society(?) / Ryoko / Ramu, but was mostly posted on dunsuls.com (discontinued ~1999). Feel free to correct me, since only the "goumon" section is posted here, and the link I once had was in the days of 64k modems :)