Unfortunately the Mackangdal + Revenged Sevenfold makes it so you, the Kabbalist would die. Not the mobs.
Mackangdal says you are invul. to all incoming damage. At the end total up all the damage you negated and inflict it all at once to yourself.
Revenged Sevenfold says the next time you would take damage, reduce the incoming damage to ‘1’ and return the damage (plus and extra % from the levels) to it’s source 7 times.
As the interaction stands RS treats the source of the damage as the Mackangdal. Mackangdal’s damage is treated as you, the target buffed by Mackangdal, as hitting yourself.
It’s kind of a long explaination, but pretty much Mackangal + RS makes it so anyone under both effects that take enough damage to kill themselves, not the monsters that hit them.