Hmm...  Do Osama Obsidian's and Medah Blackfeather's defenses include anything to protect against Polymorph effects?  Or for that matter, nausea caused by a<em>Stinking Cloud</em>spell?  I know incorporeal and gaseous creatures can't be subjected to<em>Baleful Polymorph</em>, but without either that or spell resistance/golem-style spell immunity, that spell might be a great option for Dask to achieve a surprise victory in at least the first round.  And if it doesn't work, then the cloud would make a good backup, since nausea prevents spellcasting.