鋼鉄の魔女アンネローゼ (koutetsu no majo anneroze)
https://rule34.xxx/index.php?page=post&s=view&id=5627195
The poison made her only be able to feel pleasure, and she finally reached orgasm while the tentacles ate up her innards.
I always feel a little pity, because this scene is way too vanilla for me. Hope somebody could recreate the scene in a more gory way.
Also, this one is a good reference too: 月下斬魔之花 (Gachirin ni Kirisaku) Ch.11
https://files.catbox.moe/qt7i2s.jpg
https://files.catbox.moe/9jk0l5.jpg
Girls enjoyed being eaten by a beast.