Yes, my own cat is widely regarded as "Just a Total Jerk."
If all else fails, what about a consult with a behaviorist? I know that feeling when someone suggests that you "take him back to the shelter," it's a horrible, sickening feeling. I found an alternative for the dog and worked with the shelter to do a rehoming that was acceptable to all involved and he never had to go back to the shelter, so your shelter just might be willing to work with you on rehoming if it comes to that...something to keep in mind (most shelters require that if you ever have to surrender the animal, it must come back to them, but if you can find a new home yourself, they might be happy to just oversee the paperwork).
I hope the reintroduction and spirit essences work. If I didn't have a very territorial one myself already, I'd take Boba in a NY minute. He sounds and looks like my kind of kitty...but I think he and Assumpta would kill each other...
Can you swap the play therapy so that you play with Boba and your husband with Pfeffa? And try separating them at least when your husband's not home? Maybe having your husband be the agent of intervention between Boba and Pfeffa might make a subtle change...if you're territory that both cats want, maybe having a third party do the "dirty work" might alleviate some of the territorial disputes over you (because you didn't say that they ewre acting this way to your husband)...just thinking out loud, though. Maybe a spritz of perfume on your jeans might help to confuse the scents a bit, so no one's got a clear claim.
Hmm...and a vet visit wouldn't hurt, just to make sure that no one is having any physical problem, or that there's no residual reproductive tissue or hormonal baggage hanging around in either cat...Is Pfeffa giving off any body language (tail, posture, vocalization) that might resemble heat and confuse Boba? That's why I think a behaviorist might be able to watch them interact and see where the real issues might lie.
Sorry, more thinking out loud.
I hope you find a way to deal with all of this.