NHF – new heroes for Heroes V 3.1.

The equivalent of "Path of War" already exists for a hero from the "Sylvan" faction.

Added 5 minutes later
Essentially, to create a warrior, you need to increase attack, luck, indirectly initiative, and defense. And defense will only help the mage stand longer while the hero casts spells.

Added 2 minutes later
And it should be done in a way that avoids repetition.

Added 22 minutes later
The simplest thing to do is to transfer spellcasting into attack. But that would look very bad.