Help me please? Karador on Impossible

[Sigma88]

Mage: level 25
leadership:16194
atk 9
def 15
int 24
132 mana
Wife: frog feonora

Troops full stacks:
Sea Dogs
Royal Snakes (with upgraded snake ring)
Demon (with demetrius)
Archmages
Emerald Dragon

This battle, as suggested by the difficulty, is impossible for me. It's going fine, until one of my units gets hypnosis, usually sea dogs and down goes two of my units. I am trying to use necro call on defeated units but they don't survive long enough and end up getting necro called by karador anyway.

I've just about given up. I know impossible is like impossible but didn't know it was a HUGE jump from Hard mode. I thought hard was pretty easy, at least with a warrior class, since i ended up with no casualties with the karador battle. But this just seems impossible for me with a mage.
I don't know what else i can do besides changing up troop composition and siding out archmages and emerald dragons.
And i wonder how hard baal would be.. i haven't even tried fighting him yet.

Is there anything else i could/should do to win this fight? Perhaps some of you would like to try out my save file for the heck of it. Otherwise I'll just give up and start the expansion. All i really wanted to do was play all 3 difficulties(besides easy) with all 3 classes but karador on impossible is a roadblock for me.