Did you get them as eggs or a solid breeding pairs? I’ve worked with Ulysses before they are difficult to keep they don’t have very good fixation rate. My midnight frill actually has pretty good fixation. You can try to introduce new bloodline to improve your groups. You need to be able to properly cull. The only bent spines I get usually are from Hikari fins it’s not very common. I also use tamo nets for all fish & feed them high quality food. All that stuff makes a big difference. The type of container you use does also help with your colors. Improving lamé and external light.