NHF – new heroes for Heroes V 3.1.

What about a human character whose knowledge grows? Or is it your intention to create a mage-warrior?

If you look at his starting stats and specialization, it will immediately become clear what he is for.
Increasing his knowledge will not turn him into a summoner or chaos mage.
Even if you try to make him a "Paladin" or "Fallen Knight," he won't be able to break out of that mold (he will still only be able to develop either light or dark magic).