Blood magic

'If this guy is so loyal to his master, why leave him behind like that? It's almost revolting to leave someone so loyal behind.' Valko thought with regret. He didn't imagine that Athos could make anyone loyal to him, nor that the mage was just a suicidal soldier.

No undead could force a slave to be truly loyal. They could force them to obey their orders, but the mind would remain free to think what it wanted.

Athos was the only one with the ability to corrupt souls and force the loyalty of others, but Valko had no way of knowing that.

"You seem like a good and loyal man. It's a shame your master discarded you here. I know you can't disobey the orders you've been given, but why not set aside loyalty to a master who doesn't deserve it and join us? Even with your low power, we'll treat you much better." Valko spoke with her best professional smile.