It's been another month, three in total now, so I'll give another update.
Jasper is still in the garage, surrounded by toys, haha. Today I brought him a new mouse toy and he went crazy for it. He also fetched it back to me a few times which he's never done before. It was adorable, he was meowing with it in his mouth and dropping it at my feet.
Overall, I notice he's less likely to bite. In the first week of January he sank all four of his teeth into my dad's palm, spanning across either side of it. That was pretty bad, but since then I can't recall any other incidents. He hasn't tried to attack seriously in awhile but I'm still bringing the oven mitts and leather gloves in with me. Usually only on one hand though. When we leave the room he still may take a swat at our clothing, but the last few weeks it has not involved going as far as biting us.
He's not a fan of being carried around, but I've seen far worse reactions. He doesn't turn around and bit us when we put him down anymore at least. He also seems to like tummy rubs and he lets me clean the gunk out of his eyes! Hah. Now that's progress.
Someone he didn't know was in the garage yesterday and he growled and hissed quite a few times at them and got all fluffed up, he went up to hide in his bed twice because they were in the room. I was able to call him back down to sit on my lap but I don't think it would have been pretty if the stranger had crowded his space.
We're also trying scent exchanges. Jasper acts like he might as well not even have a sense of smell as far as Blacky scented stuff goes, which I hope is a good sign...? I have no idea. He's oblivious. Blacky on the other hand has been extremely difficult. This is probably the third week, maybe more, and she's still not impressed with any of his scent. The first time she smelled him on her chair she hissed and left the room, she hasn't slept on the chair since. We've probably made some headway from that point, once I even got her to sit beside me for a few minutes on the chair, but it is really slow going. Every day we're rubbing a t-shirt on her when we feed her that smells like Jasper.
Jasper has also briefly met each of the dogs and gone nose to nose with them, he seems curious, although at least for one of them got all fluffed up.
When it gets a little warmer (March) we'll install a screen door. I can only hope Blacky has improved some by then.
I guess I won't be updating this again since he probably isn't as feral, at least around us, as he was back when I created this. Now it's more an issue of introduction which is still serious... I might make another thread for that in a month or so.
On another note: I hope everything is going smoothly for you, Saly.