The Challenge in Dwarven Land

[BuffaloX]

I was level 14 mage when I hit this, I went back to kings castle, bought a bunch of useless units, I ended with only a few commanders so I had to use invisibility.
but guess what, then he just cast geyser, and that worked on my lonely invisible stack, only 4 survived, but luckily he was out of mana, I had my 4 commanders run away like h... and took out the remaining stacks with fire arrow.
I suppose next time I have to use slightly more clever strategy.

PS I only one on my third try, got totally smashed the first time.