The first six volumes are probably the same as these: https://nyaa.si/view/1127769. There's https://nyaa.si/view/1128108 with the remaining two volumes, but it's unseeded and judging file names and sizes, aren't the same releases as of this upload.
Outlanders (アウトランダーズ Autorandāzu?) is a popular manga comic written by Johji Manabe, combining aspects of the Space Opera, Science Fantasy, fan service, Magical girlfriend and Harem genres. It tells the story of alien Princess Kahm and Tokyo News Photographer Wakatsuki Tetsuya as they try to save the earth from the invasion forces led Kahm's father, emperor of the interstellar Santovasku Empire. The Santovasku use giant organic spaceships, or "Biomech," and they utilize both their advanced technology as well as their mastery of sorcery in their assault on Earth. Wakatsuki Tetsuya discovers from Kahm that her ancestors in fact came from earth and they've returned to reclaim their sacred home planet that mankind has subsequently spoiled (due to pollution).