Dark eye

I lifted my knife from the skin of the little girl and wiped my bloody hands onto my clothes without thinking. Then I looked through the lines that I carved all over its skin, which was smooth and complex. 

After that, I poured my mana into the lines that were on its skin and dropped a few drops of healing potion on these cuts. 

While the mana was flowing through the rune lines, the cuts closed because of the healing potion but the mana already spread through the lines and stood there as if it was stuck by the flesh that had grown. 

Well, this method was something I have just created right now and I didn't know if it would work. But it was worth a shot. 

If it works, according to my guesses and theories, the low rank regeneration would be permanently ingrained in the undead little girl's skin. Without any need to engrave again and again to the skin that got deep injuries, as it would interfere with the lines of the runes.