"We have been trying to pass all of our mana to the crystal, but it is hard to make people come and go all the time," Julia said.
"I imagined that… it can't be helped, we will have to sacrifice some monsters," Luke said.
"Really? All of them have helped us…" Julia said with a sad expression on her face.
While she was allergic to cats, Julia liked them and pretty much all kinds of animals. The monsters tamed by Luke and their offspring were much the same to her… and that complicated things. He wanted to make things right and protect his family, so he couldn't afford to be picky about the how.
"Mom, the crystal only accepts the sacrifice of loyal creatures, so I can only use those that are obedient to me," Luke explained.