Transmigrating to Another World to Build an Adeptus Astartes Legion

The original owner was set up by his stepmother and lost most of the family fortune, leaving him with no choice but to head to the Southern Continent and inherit a fief. The body is taken over by a down-and-out author from Blue Star, who was in the middle of playing Warhammer.

But he awakens Fulgrim's template, and can earn a gene-seed for every seven-day sign-in! After careful consideration, he decides to build an Astartes Legion!

Conquer the Southern Continent, seize the planet, complete the Great Crusade, unite the galaxy, and establish the Imperium of Man!

Bah! He must have been possessed by a fox spirit just now.

And so, while whipping the capitalists, he builds the Emperor's Children Legion and becomes the greatest conqueror this world has ever known!