i started to play it too. i'm playing impossible warrior and i've just defeated "monster from abyss"
i'm using engineers/droids combo (i sneaked to Bolo to steal 'em
) and they are really powerful together, have no losses so far. i tried rune mage too, but since i can have right now only one, it isn't very impressive, but in greater numbers and more unspent runes, they could be powerful as well.
i'm planning switch to orcs later when they become available in greater numbers. they seem very interesting with their new adrenalin related abilities.