Discussion of the Necropolis faction.

I have a question: when a hero levels up, they receive points to spend on combat skills, magic, or the hero's personal skills.
Can you explain how the hero's personal skills are leveled up? I've reached level 10 and can't seem to increase the Necromancy skill.
Also, in battle, a hero playing as a Necromancer can resurrect units using the Necromancy skill bar, not magic. But what's the difference if I use only a quarter of the bar or the whole thing? I've tried both ways, and the result is the same...[/QUOTE
Friends, help me! For some reason, the Necromancy skill isn't working in battle. I'm already on the second mission of the second campaign, and I can't use it. What's the problem, and who can help?