“I don’t like the sound of either comparison,” spat out Birdway. “That thing has dissolved all of the fat in Patricia’s body and slips inside the empty space to maintain her human silhouette. It also handles the storage and distribution of nutrients that the fat would have. In other words, that thing holds my sister’s life in its hands. Try to extract it and it will go nuts and tear her body to shreds. And even if you did successfully suck it out, all that would remain is an empty skin-and-bones shell of my sister. She would die before she could recover her strength. In other words, she can’t be saved by normal means.”

Toaru Majutsu no Index New Testament vol.14 ch.2 pt.6