I would think mutations considered safe for the blob might not be equally safe for the human body. While the mutations currently implemented are mostly beneficial to both parties, some… disintegration for example. That’s straightup bad. Blob inside you doesn’t have the mass to survive without a host, unlike the larger blob monsters you fight, so it’s in both parties best interests that the human portion stay alive. I always imagined disintigration as the blob in you trying to alter itself in a way that would be beneficial to itself, but detrimental to you. It’s not perfect at adapting to its environment every time either.
Any sort of ‘zombie’ or ‘extreme blob’ mutation branch would likely be very destructive toward the host body imo. I like where Azrad is going. I wouldn’t want you to become ‘zombie faction’. I know somewhere it was stated that populations of blob that have mutated to be sufficiently different may no longer be recognized by past ‘parent’ blobs. You would be like a rogue blob state as far as the larger zombie population is concerned. Lorewise, I wouldn’t label a new branch like this a ‘zombie’ mutation branch, but something to express this blob-human incompatibility.
You know what it’d be like gameplay wise? It’d be like playing a black phyrexian deck in Magic the Gathering. Or Dragon age’s Blood mages. Pay one life, do one damage. Lose two health, draw two cards. Just, …basically, turn your health pool into a power source, at your own risk.