Portraits revealed through your current reading position.
In the epilogue, Dr. Hu goes 'all in' on Carl over his associate's objections — hinting the mystery yam has a secret purpose Carl only half-grasps.
Porthus, as 'Dr. Hu,' opens the epilogue in conversation with a skeptical associate about the fortune the NFC has poured into Carl. She calls Carl insane, unstable, and doomed — likely dead before the sixth floor, with the AI going primal, the Valtay meddling, a kua-tin civil war brewing, and King Rust's children and Princess D'Nadia in play — and complains he 'wasted half' the mystery yam saving Chris instead of using it for its real, undisclosed purpose. Dr. Hu is unmoved: 'He knows what it's really for,' and 'We're going all in on him.' Even if Carl fails, every appearance on Odette's show recruits more to the cause — which Dr. Hu insists is one and the same as the NFC's.
His faith is total: 'That's what you said about the fifth floor.'
Unseen this scene beyond being 'Dr. Hu'; a long-lived former crawler running the NFC from outside the dungeon.
Carl's covert backer, betting everything on him despite his associate's doubts.
Also appears in books you've already read — spoiler-safe to their endings: