Bloodmate's Bond Cat LeDevic
Dark cover with red (such as blood) popping maybe? One idea: golden chalice on its side, blood pouring into pool on small round table in front of heavy closed curtains.
Another thought: a couple surrounded by white mist with a faint bond linking their hearts or around them: the chalice at their feet, blood on floor.
Another is a series of framed objects down a hallway: can't tell what they are until you get a good look at one near end, which has a cameo on a black ribbon around it. Necks, of course! Perhaps faint puncture marks on one?
No gore, overly violent overtones. My vampires are extremely classy. (The neck art hangs in the king's suite on his plane.)
These are only ideas: feel free to be very creative!