It's the campaign from Shades of Darkness, for Gem.
The enemy has:
Charne with stats 13, 16, 10, 9
18 Bone Dragons + 210 Ghosts + 114 Liches + 44 Upgraded Dark Knights + 124 Vampire Lords + 14 Unupgraded Dark Knights
+ She has the Vulnerability Aura and a Ring of Swiftness, Expert Tactics, and casts Raise Dead.
My army:
Gem, 17, 16, 12, 16 (Earth, Water, Archery - Expert, Air - Advanced)
15 Gold Dragons + 197 Grand Elves + 210 Grand Gnomes + 34 Grand Unicorns + 69 Dendroids + 40 Grand Pegasi + 280 Grand Centaurs.
Basically, no matter how I try, I can't win manually, although the quick combat manages to win, while maintaining 70 mana, 3 dragons, 180 elves, 200 centaurs, and some other units. I don't understand how. Moreover, if I change the troop arrangement, the result varies, from large losses to defeat.
I thought I'd watch the auto-combat to see how it wins, but in auto-combat, it gets even worse than I do... =)