Unfortunately I cannot get a third cat and while I’ve been open to rehoming Mina if I absolutely must, I’m not sure he would be a good candidate with his craziness. My husband doesn’t think I should rehome him, and considering that my husband doesn’t even like Mina all that much, I’m inclined to trust his judgment. He thinks I’m overreacting. And while I don’t know if I agree, I’ll at least admit my stress over the situation is affecting my ability to think objectively.
Then there’s the likely reality that if I rehome Mina, Merlin will die soon after - he’s getting up in years - and then I will have gotten rid of my beloved kitten for nothing. I just don’t want to give up on them without putting in an honest effort to make things work. People are so quick to give up on cats, and I get it, because it’s really frustrating to deal with so many behavioral problems, but I’m not ready to give up. I love them both.
Yeah, I think it’s too late for a living toy, now, sadly.
In all honesty - I think the solution here is to just wait it out. The teenager will grow up. The old cat will calm down. They will figure out their personal relationships in time.
In the meantime, if he hisses or swipes at you - for real, I mean, not for play - don’t hesitate to remind him that you are a great ape and you are not amused by his attitude. Don’t hurt him, obviously, but act a little apeshit and let him know that he’s crossed a line.
That is an awesome cat tree. Windows are great for these. If you get a supply of the mice you can re-attach new victims as needed. We also used to take dried catnip and rub it on the tree to attract the cats to spend time more time on it.