Except I'd rather keep my brimstone eater for the quanta production.
Also since it is atk based you're sacrificing a large potential damage source, which I tend to see as negative here.
Also under most circumstances I'd probably choose a fire spirit/spectre
Ofc that's the mono fire perspective
Now duo'd with death, it's a bit more interesting as it serves as a cheap way to kill off creatures. As rut said this would combo very well with boneyard. However death already has vulture which does the stat gain passively.
Using them together? Probably not a bad idea, but I don't see it becoming particularly effective.
What am trying to say? Neat idea, poor for mono-fire, possible duo power.
Overall too weak imo.