What external components can I used besides slayer set to increase my health for descendants like Freyna and Bunny?

I’ve been been maxing out my ultimate descendant but I’ve begun running into a problem where I have around 6-7k hp and find myself running from the enemies. I’m using the slayer set but I need more health especially for descendants like bunny. What are some other ways I can increase my health with external components? Also I know 19k defense doesn’t mean anything after 5k