Well, we know Eugene was contracted as the pillar of light magic user... but it wasn't his own "special magic".
But I think his magic is stronger than regular knight's magic... because his occupational magic was that of "a knight" probably and adding to this the power of bloodline... it should be strong one.
Oh lol, maybe I didn't translate it clear enough...
- the holy spirits yell inside Minami's head to "remember" when he receives some damage,
- Minami tries to, but gets headache and falls asleep,
- Minami wakes up and he DOESN'T REMEMBER about it at all... like "did I say something...?" kind of thing.
So Minami, before passing out, told this to Yamada. So Yamada can discuss it with other priests etc. but he himself won't remember telling Yamada such a thing.