jk... o 3 o

Even though it's not written law, everyone knows that Viruses should not possess creatures with a strong core as the Virus can corrupt their core/magic and create a demon.

Human/Mage possession should not be done since it'll create strong demons. Longer the viruses possess the body, they more corrupted the core gets.

Normal animals or creatures with weak core and magic do not get corrupted.

So, random character mage Rem almost dies > gets possessed > quick shadow patch job by Virus until he finds a Alluvian > Alluvian heals Rem but she is still a demon, oops > Alluvian is now mini :( > happy ending?

Now feed her souls/cores to keep her happy （｀〇Д〇）