Even the kiritsugu are shocked by the slightest display of suffering, so it's not much of a stretch to say some images exist that would permanently traumatize all Superhappies.

This is not going to work. The kiritsugu learned about the Babyeater culture without being impaired. Nothing humanity can reasonably come up with in the relevant timeframe will come close to that knowledge in shock-value.

Note that the kiritsugu as depicted through Cultural Translater versions 2 and 3 doesn't show any shock at humans being stressed; that depiction only appears in version 16. As such, it seems likely that this depiction is not based on the kiritsugu's actual emotional state, but rather added to better allow humans to communicate with ver.