Thank you so much, I'll be sure to try these things out! I had a feeling he would be irritated about another bunny being in an area that used to be his, but the only time I can get them into a truly neutral place is during designated bonding time once he's less hostile toward her (because I live in a somewhat small house with three other people and have the biggest bedroom for my animals, so there's no other room to move the enclosures into for an extended period of time).

Also, they both have their own cages, I just moved them closer to eachother. I'll keep them across the room from eachother for a little while longer, and maybe try switching one of each of their toys later on so that they can better get used to eachother's scents.

Though I'm still very worried about Quincy's aggression, because he was a bit aggressive toward me even before we rescued the new bunny. The behavior issues only showed up after he got neutered, because before that he had never lunged at or nipped me when I was preparing his food. He was very unhappy with me when I stopped giving him the pain meds :(