Very well done, gentlemen! There's a few stories on this forum I come back and read regularly, and I'm fairly certain this is going to end up being one of those.
I especially enjoyed how much you leaned into the ideas of the virus being moldable and controllable in some ways. The intentional destruction or alteration of each convert's psyche ended up being a lot more of a turn on than I expected it to be. I know it's always been seen as a part of the process, whether in y'all's main story or in the original version by Puplucky, but it always felt like a side effect. Making it an option, a choice, added a side to the entire process that is amazingly captivating, and in some ways was the biggest turn on in the story to me.
Having variations in the mutations is another great idea, as well. I feel like that could be something you could have a lot of fun with in the story, if you decide to carry it over to the main storyline. Could allow you to lean into some interesting body horror, or different ways to claim more converts.
There's this idea that popped into my head, too, when I was reading the parts about the new converts feeding their untainted seed to the brothers to strengthen them and accelerate their conversion. Something about keeping un-mutated converts around to feed the brotherhood. Maybe broken mentally, or participating willingly, with the expectation that after they provide enough untainted seed, they would eventually be turned as well. Starts feeling kinda vampire-y the longer I stretch the analogy out, but still kinda hot. Or maybe somehow a different mutation effects the entire body of a convert but somehow doesn't affect his balls? I dunno, but the ideas are fun to play with.
Regardless, I appreciate you sharing this story with us, and sparking so many fun ideas/fantasies for me in the process. Look forward to the next installment of the main story!