I (f27) moved in with roommates (m32) about 2 years ago. With the apartment came an orange boy. He was left behind by his owner who still comes to visit in occasion. He’s about 4-5 years now and is sweet but also very temperamental, apparently after asking my roommates he is half feral when they found him as a kitten. In October my bf (30) brought home a very sweet tuxedo female that he found at work. She was extremely malnourished when he brought her home. She’s about 8-9 months now. The vet suspected that she was born last July/august. Both pets are fixed. He was neutered at about a year old. She was spayed in January because we had some tom cats coming around our apartment trying to get into the house.

I’ve been attacked twice by my orange cat due to these stray tom cats showing up to our balcony crying to get in. The first time I was coming inside the house. Had pet the stray and my cat smelled the stray on me, chased me to my room and attacked my legs and arms very bad. In the process of pulling him off of me, our orange broke his rear nail and had to have it surgically removed and it’s growing back now. At this point he has never turned on our kitten, they actually played fine until the second attack when I was cooking dinner, our glass door to the balcony was open, screen door closed for ventilation and the tom cat came to our door. Our orange turned on my tuxedo and I ran to pick her up and lock ourselves in my room and he attacked me again. Since the last attack he’s been hunting my tuxedo girl and even swats and hisses at her when she tries to initiate play with him. He follows her to the litter box sometimes so I’m monitoring to see if she’s using the bathroom now. We have separated them for a couple of weeks almost a month now, been feeding them between doors and they’re fine introduced them back together and he’s back to hunting her. He also will groom her in her sleep and pin her down and then begin to bite her really bad. There’s a big difference in size between them and I’m afraid he’s going to kill her. Our vet mentioned maybe a brain tumor as this sudden aggression is very weird 

TDLR: my older cat is hunting and bullying our kitten  as a form of redirecting his anger from outdoor strays. Not sure what to do, if I should rehome, euthanize which vet recommended as he’s attacked people 4 times now, me being 3 of those times 

I don’t know what to do with my cats