I searched for "blood slaves" and this thread didn't come up as a result, so ...
Blood slaves on fire! Blood slaves slaved to Abysian units burn just like anyone else - but you don't get to reposition them away from your fiery mage.
Admittedly they're just there for a brief time
, but you'd think Abysian blood slaves would wear asbestos shrouds until their PROPER time to die.