Red Card

The Red Card is an algorithm which is similar to the Blue Card that appears in Digimon Tamers.

Written by Shibumi, it was intentionally made to alter the wavelengths of the Digimon’s digital composition to match that of the D-Reaper, enabling them to fight within it without suffering any effects. However, there was a key element missing from the card’s design, and Shibumi eventually realized that when writing the algorithm, he had neglected to take into account the nature the Human-Digimon hybrids, which would mean changing the complex wavelengths of the humans. Due to this, they reverted back to their respective Human and Digimon forms.