7th Ed. magic armies in 8th

Another thing to consider with a Lore of Death Slann is that you stand good odds of killing yourself with the purple sun. If you roll a misfire on the artillery die, you center the template over the slann and scatter d6 in a random direction...That's a 2/3 chance of a dead slann, along with innumerable dead lizards...not sure if it's worth that sort of risk.

 

Not sure if this would work but take the 3 skink priests on foot then give the slann lore of beasts with focus of mystery and unfathomable prescence. The idea is to throw dice at the transform into dragon spell, or the lower level if you don't feel up to it, and cast through the skink priests.
Another thing is ,if you have the points to spare, take higher conciousness and because you keep special rules when you transform you can take a magic resistant and immune to normal attacks dragon.

 

Can only channel magic missiles through the skink priests.

As far as I can tell, you WOULD still be ethereal if the Slann can transform himself into a dragon. The only thing I am fairly sure you can't do is transform the Slann, since he is not "on foot". This is something I think needs to be FAQ'd.