He called one of the skeletons that had already been healed and told him to soak up the nutrients in the hay until his body returned to its prime. The skeleton obeyed, picking up the hay in its hands and stuffing it into its mouth, the hay quickly wilting in its jaws to dust.
One of the things that Athos noticed about the skeletons is that they all gained the ability to manipulate their own core. He initially thought it was because they were monsters, but looking at the skeleton in front of him, Athos can be sure. Even if they were ordinary villagers, mages, or monsters, all of their skeletons could handle mana to some degree.
This may have come as a shock to Athos, but it was obvious. As he himself had already realized, the black skeletons are created from a pulse of dark magic released by the core itself, stimulating it at the moment of creation of the undead.
'It increases their potential. When things calm down, I should train them to the bone and see if any of them have the potential to become a mage.' That's what Athos thought after recovering from the shock. He watched intently as the skeleton devoured the hay until it reached its summit. His bones didn't seem any thinner and had returned to normal, even seemed a little brighter, but it must have been all in his head.
"Very well, now go back to the others. All those who have already been healed, eat until you are full. Those who are injured, come to me and I will heal them. Also, the four of you should join me and assist in the healing. . You're already mages and you've gained an affinity with the dark, it's a good way to practice." Athos spoke, looking at the four mage skeletons in the distance.
They obeyed him, but Athos sensed their hesitation, as if doubting whether they would really be able to use dark magic. They took out their wands and started trying to accumulate darkness, being shocked when they actually succeeded. Athos didn't know how he managed to see all these expressions on a faceless skull, but he found it amusing to see what he assumed was an expression of astonishment.
Perhaps because they were more experienced than he was, the Skeleton Wizards had an easier time controlling dark magic, but they seemed to be struggling to separate the darkness from the world's energy with their wands. Athos didn't know this, but wands were made using branches of magic trees, mixed with magic stones from the elements that mages had an affinity for.
Of course, none of this group's mage had an affinity for darkness, so none of their wands could draw the darkness of the world's energy. What they were doing instead was attracting the pure world energy and using pure willpower to extract only the darkness. This method was incredibly inefficient and gave skeleton wizards a terrible headache just for trying, but they persisted in the task nonetheless, unable to disobey.
Now with 4 mages healing the skeletons, the process is much faster. Even so, it took up to half an hour before dawn for the last skeleton to be fully healed. The undead crushed by the boar skeletons took a long time to heal as countless bones were crushed to dust. He had to ask the skeletons to collect the pieces or even the entire village reserve for the winter wouldn't have been able to heal them all.
When Athos was finally finished, he breathed a sigh of relief before dropping to the ground, a terrible headache from overusing mana and focus. Despite having infinite physical stamina, the undead still seemed to suffer from mental attrition. The mage skeletons also appeared to be suffering, but Athos did not let them rest.
"Which of you is the former leader of the mages? I have a little experiment I want to do." Athos asked.
One of the skeletons raised his hand. He was wearing the robe of one of the mages that Athos failed to turn into undead, as Athos was wearing his robe. Athos had taken most of the magic items for himself, but he saw no problem distributing the rest among the skeletons.
"Fine, now I need one of you to hunt something. It might just be a little mouse, it doesn't matter. Just make sure you bring it to me alive." Athos spoke, this time looking at the skeletons above him. They were the bladed bird skeletons, the only ones able to fly among their undead.
Despite being made only of bones like the others, there was a thin layer of darkness around theirs allowing them to fly and use their species' characteristic ability, transform their own feathers into blades as hard as iron and shoot it. When he activated his ability, the thin layer of darkness on his wings would turn into several small blades before firing, and they could easily regenerate by consuming mana.
Athos had ordered them not to participate in the fight and to act as scouts, making sure that no villagers escaped. They were the fewest among their skeletons, having only eleven of them, including a leader. The bird skeletons whistled in agreement, before spreading throughout the village. They returned a few minutes later, carrying live rats on their talons.
The rats squeaked as Athos took them in his hand, jabbing their bellies with the tip of his bony finger so as not to damage the bones. He wanted the mice alive to ensure the skeletons were intact. There were seven mice in total, more than enough for his experiment.
"Turn him into an undead." Athos handed the leader one of the dead rats, watching intently. Up until now, he had created each skeleton personally, but if other skeletons beside him could as well, he could split his efforts and attack more than one village at the same time.
The lead skeleton took the mouse in its hands and looked at it questioningly, not knowing what to do. It seemed that the knowledge of how to turn others into the undead was not instinctive.
"Use the darkness to absorb the corpse's vitality, but don't devour it. Instead, make the energy pool in the rat's chest, where the core should be, and ignite it with a spark of your own life force." Athos explained, before quickly adding. "Don't worry, your life force will recover once the mouse turns into a skeleton."
A light of understanding shone in his empty eye sockets and he did as instructed. The rat skeleton was successfully created, but there was a difference. The spark of life force spent by the mage leader was regained, but the extra life force flowed through the link between him and the leader, strengthening him. It seemed that even when another skeleton created an undead, he was strengthened.
"Fine, fine, now it's your turn. Try to turn them into an undead." Athos caught two mice, handing them over to the skeleton of a random villager and a rock bear. All skeletons were created the same and they all gained an affinity for darkness, so there's no reason they're unable to create undead either.
...Athos couldn't be more wrong. The human skeleton was totally ignorant about mana and didn't understand his explanation of life force even after he explained it in detail. He wasn't able to release enough energy to consume the rat in one go and on a second try, he released too much energy and turned the rat to dust.
The rock bear fared a little better, as it instinctively knew how to manipulate mana. He was able to absorb all of the rats without destroying the skeleton, but he was unable to use life force to lift the rat.
"It's a shame it didn't work. It would be an amazing skill if all skeletons could create other skeletons while still fighting. My mana isn't infinite after all." Athos spoke, using dark vision to see the nearly empty core, the corrupted version of mana vision.
He had tried and failed to use death vision to see the core of living monsters, but it worked normally on undead. He was also able to see some kind of shadow on the monsters' bodies, but he didn't understand what it was. The shadow moved in certain patterns depending on the monster, but Athos didn't see any shadows when he killed the villagers.
Leaving the matter aside, Athos focused again on the present. "I've made a decision. We're going to split into two groups from now on. The first group will be led by me, the other by the mage leader here."