The Master Necromancer - Vol 1 - Chapter 46

For Skraal finding a dead human body with "Magical Stones" is not hard at all.

He went to "Market Cemetery" where dead human corpses were sold by the families of the deceased, compared to just bury them they wanted to earn some funds from the death of their loved ones and at the same time help the improvement of magical studies.

Of course, the latter was just a big lie many of them cared about the Magical Stones they are going to earn from the corpse.

After Skraal bought about six human corpses all of the human corpses were delivered to his house and he is the one who put them on metal tables in his underground base.

He used basic magical energy for stopping the process of decaying.

He bought three male corpses and three female corpses all of the adults and all of them died because of sickness and other natural causes at a young age.