There is, indeed, nothing pleasurable or even mildly pleasant about being ripped open and pulled apart piece by piece. The victim can't even be promised a swift death. They'd feel so much of what's happening to them before they finally succumbed to the pain and injuries. They would suffer immensely before they ever died. Then the family wouldn't even have anything left to grieve. The victim would simply cease to be.

Vena gives them a slow, pleasurable death, and leaves the loved ones with a body to mourn. Which is also why he's a different kind of problem.

Stepping even closer to the other creature, Vena reaches out to take Su-jin's hand and presses it to his stomach. "I can't imagine they want me leaving corpses at all. I believe their preference is that you feast on me."