I adopted a roughly 8 week old kitten just over 2 months ago. I did the introductions feeding at the other side of the door, supervised time etc. and although my resident 3 year old would sometimes play with the kitten on his terms he was still hissing and swatting him. My kitten then sustained an injury (unrelated to resident cat) and had to be on cage rest for 1 week. So I took that as an opportunity to do a reintroduction by feeding them at either side of the cage. Resident cat would still sometimes growl while eating. I've now taken the kitten out of the cage gradually for a few hours per day for the past few days but now their relationship is worse than ever. They still play together when my resident cat is in the mood, but if he is not in the mood and my kitten gets too close then he will aggressively growl, swat and corner the kitten at least 20-30 times per day. Although he isn't using his nails I'm just worried that this is going to escalate and cause the kitten a serious injury. The kitten however doesn't seem that bothered by it at all and is not acting scared but I do feel like his quality of life is suffering. I currently live in a large 3 bedroom apartment but I am going to be moving abroad to a small 1 bedroom apartment, and I can't imagine having to deal with this aggression and conflict in such a small space, plus it's a big ordeal to put them through by moving abroad. I absolutely love both of them and consider them to be my family members but I really do feel that the kitten's quality of life is suffering because of my resident cat's aggression so I wonder if it would be better for him to be rehomed before I start the process of moving in a few weeks. Any help/advice would be much appreciated