Darfilla provides the flame and lashes out with a tongue of arcane fire that scorches the Ghast nearly defeated by her employer as well as several further out. The nearest one succumbs to its injuries but the others continue onward.
One of the singed creatures is fully under Morwen's spell and has lost any semblance of self-preservation. Such is the power of the Ravenkin's black arts. A mortal might throw off an enchantment that turned them against friends or if harmed by the caster's ally. But the undead have no morals and so they have no defense against any action they are compelled to take.
But there are yet more undead closing fast!
Both PCs save and no longer need to worry about the smell.
Both were hit by the Ghasts though and must save vs paralysis.
JJh's Ghast is slain.
Round 2
2 More Ghasts and 8 more Ghouls join the melee.
Archers may loose a volley (including heavy crossbows)
JJh takes one of the Ghasts. He may choose to face both or he can force the second to fight either himself and Bofur, or himself, Morphin and Verdugo.
Everyone else in the melee line will get fresh ghouls.