Developing a Knight hero from the Haven faction.

You can never have too much healing, but regeneration is a weaker form of healing. As for "Aggressor" and "Defender," I disagree. There are already plenty of buffs in the Campaigns, and these are just a waste of skill points. It's better to learn something interesting from magic instead.

Of course, you usually use healing, but sometimes, for a lossless game, it's good to have something you can cast after healing. Although, for the Alliance with two units of Adepts + Seraphim, it usually doesn't come to regeneration...
I didn't mind spending 1 point on +3 to attack or defense, as after level 25, there wasn't much else to upgrade. A Warrior with his magical power doesn't get much benefit from magic. And the first 2 levels of magic don't offer much... I took "Taunt," but I only used it once during the entire campaign – just to see what it does. I also took "Fear," but it turned out to be unnecessary; 95% of battles were won in 2-3 rounds, following a pattern: push the enemy, heal your own. In special cases, I used "Forward" to attack immediately, and I also summoned Phoenixes against archers.