So, how have you guys been able to defeat Leandra?
I kill the three demons/dinosaurs looking things one by one. But when she spawns the fire thingy, I'm getting fubard in all holes. When I've gotten so far as destroying all the protection auras the fire thingy have spawned, I'm more or less dead and I barely get to touch Leandra.

Can't go back and change anything as I don't have any earlier save except all the ones I've created in this backwards world.
Thinking about looking for cheats.

Sneaking into the battle you should be able to cast "Hail Storm" and freeze her before she gets protected.

Use up any summon scrolls to surround her with summoned creatures, plus use knockdown or stun abilities on everything.
Summoned creatures are great for soaking up attacks.

There is a vendor after the Leandra fight, so don't be paranoid about running out of scrolls/potions.