How you kill Ktahu

[smikkel]

I 've got a level 52 palladin on easy level and can't even get a dent in this monster before being utterly destroyed.
Army consists of 11 black dragons, 13 red dragons, 280 inquisitors, 10 tirex and 14 archdemons. I tried also with palladins instead of archdemons, but there are only 36 left on Teeana, so they 're quickly eliminated.
I 'm wielding the singing dagger.
Why does K'tahu not summon armies on the video in post 1 ? On the second turn I get a bunch of brontors and tirexes around my troops (disabling missile attacks from the inquisitors) and on round 5 or 6, additional lizard men shamans, brontors and those pterodactyl beasts. Game over.