Karl was frying the lamb heart for the mirror curse. The child had to witness the butchering of the animal. The necromancer had numbed the lamb to the point where it fell into a coma, then he had slit its throat.
As the blood gushed out like a fountain, little Elidys had broken down and had begun to cry. That was a good sign. It meant that the curse was a recent development.
Had it been something that had been laid on him since birth, his brain would have been inadvertently altered. He'd think that cruelty was normal, and then he would get himself killed.
He looked down at the toddler, his ember eyes for once not finding any mirth in the pain of others. The child would grow to be a little idealist, just like Eddy. Maybe the country would welcome him, or he would still get himself killed.