When Eisen finished all of these base things up already, he started trying to figure out the best structure for the rest of the Fox's body. After all, he would need to construct it around the blood and mana veins now, and even though they weren't just as complex as the regular circulatory system was, they still they were still something that was relatively tough to work around, but Eisen ended up managing this just fine.
Send some love to my second novel, Demon's Virtue!
https://www.webnovel.com/book/15238973305579305/Demon's-Virtue