The planet Dedru was inhabited by the Dedru, who were still in the age of cold weapons. Yet because they could make use of the Spirit Realm, although their materials science remained at the level of wood, they had entered space early on and discovered that their entire race lived on a sphere.
This was a highly developed civilization reliant on the Spirit Realm. Correspondingly, it also practiced extremely cruel religious human sacrifices. Before fanatics, reverence for death was naturally nonexistent. So long as they could please their "god," they would not hesitate to offer everything, including their lives.
After praying to the Spirit Realm for a bloodline that could survive normally in space, the Dedru entered space as a civilization still in the cold-weapons era.
Warships resembling wooden sailing vessels traveled through star systems, establishing castles that floated in space and continuously expanding their territory.
With no firearms, space combat centered on boarding actions. Powerful warriors capable of adapting to the battlefield often stood out in boarding battles, and thus became the key targets of Dedru civilization's cultivation.
Six hundred years ago, they were discovered by the insectoids, who began their invasion.
There was no question that it was an absolute slaughter. Engaging the insectoids in close-quarters boarding combat was not a wise decision at all. Even if cold weapons could break through the insectoids' outer biological armor, the insect acid spraying from inside their bodies would immediately claim the Dedru warrior's life.
Even if the Dedru feared no sacrifice, the outcome would not change. The insectoids also feared no sacrifice. In the end, it became a contest of numbers between the two races.
Naturally, the insectoids, who possessed biotechnology, held the advantage in numbers.
On the eve of civilization's destruction, the high priest of Dedru civilization stepped forward.