Poor bears & co.

[BB Shockwave]

Why are you using Demonologists by themselves - they work best with demons?

Ancient Vamps are evil, yes. And the AI cheats. I used them in my last The Legend Walkthrough (all-Undead game, Bone Dragons, Necros, Ancient Vampires, Black Knights, Cursed Ghosts/Skeleton Archers) and in Death Land, their evasion ability kicked in like, 50% more often for the enemy then my own ones. One way to deal with this is by forcing them to change form, and then using Magic Lock to trap them in that form - usually if they can just reach one of your units in bat form, they will transform.

And Griffins are great units, at least they served me well in The Legend. My first walkthrough, I had Black Dragons, Royal Snakes, Griffins, Orc Shamans and Evil Beholders/Inquisitors. After Royal Snakes, my Griffins dealt the most damage. They have high HP, good defense, just put Stoneskin or God Armour on them and place them in the middle of some enemy shooters and watch them attack in vain.

Of course, in AP they are not that strong compared to some higher level units, but that's why we have Royal Griffins. They double as summoners, and the Heavenly Guardians are awesome - they are very resistant to physical attacks, and the best is, they ignore negative spells. I beat Hagni with them easily, she was wasting her mana by casting Hypnotize on the Heavenly Guardians - the spell works, but then immediatly disappears.