Help me please? Karador on Impossible

[Sigma88]

Baal was retarded easy and I just beat the game. It took me about 10 tries to see what other methods i can use to fight the horde of enemies from the last boss. The ancient ents were the biggest problem, they have extremely high defense and i could only kill 1 or 2 per turn... and there's about 65 of them, 3 stacks each having 20, 23, 22.
My team was the following:
15 Archdemons
104 Demons
14 Cyclops
13 emerald dragons
23 Ogres.

The only reason why i choose this group was so i don't get controlled every turn since my troops were all level 5s and last boss kept casting sheep/hynosis/pygmy. In all honest truth the cyclops were very useless, i should've used Bone dragons, they are actually MUCH better. The only reason why i didn't consider them was because i thought all undeads were weak to fire but not really.

My first few attempts i was about to give up. My troops were:
Archdemons
Demons
Royal Snakes
Sea Dogs
Skeleton Archers/Ogres

It didn't work, closest i got to was destroyed all dragons and left with 2 stacks of 20 ancient ents, then got obliterated. That's why i had to change up my troop composition and got the idea of using just 1 stack that's not level 5.

MVP troop: Archdemons. Don't underestimate them when compared to 2000 sprites or something. Divine armor + stone skin. Damage from 20 ancient ents, theoretically 2000. With both buffs, reduced to a measily 70.

Lastly I went and killed every enemy i had left over and luckly leveled up at the last enemy to 30 and got a leadership option. Final leadership 20900+ and that's without any equipment that gives me leadership. Also i used 10 rats so i should have 500 more.

P.S. I am not playing impossible mode again.