The commander could knight anyone he wanted to but it would take recognition from the Royal Knights and ultimately the king for Henry to ever get further than Hydrogia. Commander Lothian saw more than being an average Knight of Hydrogia in Henry's future but he didn't want to overload him with his thoughts.
"I-I…" Henry's eyes widened and he looked at each of the men present, searching for one of them to tell him that it was a joke. Perhaps the commander was only saying things because he had been drinking. "I've only just started, commander. There have to be other apprentices more suited to become knights."
"You've been with us for over two years," the commander objected. "No other apprentice, even from the Royal Knights, was actively putting themselves into danger to save others or fight monsters."