Eric wasn't afraid of humans knowing he could use magic; he just found explaining troublesome and didn't want to attract attention.
Since it was just Henry alone, telling him was fine.
"You guessed right; the magic was cast by me. Perhaps because I was born weak and didn't have as good magic resistance as other beastmen, it conversely gave me the potential to become a mage," he said seriously.
Even to his tribesmen, Eric explained it this way. He couldn't say it was because the soul inside had changed to a human that he accidentally learned magic.
Henry spoke thoughtfully: "Indeed, that day in the camp, my feeling was not wrong. The person who knew magic wasn't him, but you, Patriarch."
Mentioning letting Arthur take the blame, Eric felt a bit unnatural and scratched his head: "There were too many people around at that time; I am a person who fears trouble."
