This gets scary with things like Malignant cell or Phoenix because of the exponential increase. Imagine - kill one phoenix, get two ashes, rebirth for four phoenixes, and if you manage to kill those four, you get eight ashes, which you can rebirth to get 16 phoenixes. This can be done with a life mark and two immolations to get the quanta for Dry spell.
Also, does Fate egg apply? If so, would it generate the same creature, or two random ones?
I don't think this should apply to flying weapon, since Mitosis doesn't either.
Edit: And what about Graboid? And Reverse time on Mummies?