The Shadow Dragon Ritual experiment was tentatively a success, but the duration was discouragingly short.
Ybur inquired and found out that the main reason Saraphido struggled so much was due to its large size.
The Shadow Dragon had attached itself to Saraphido, using it as the host. Thus, it was of Fourth Rank and immensely large. However, the Sustainer turned out not to be Ybur himself, but Saraphido... Saraphido simply couldn't sustain such a drain, barely lasting a minute before giving out.
...Ybur actually estimated that even if it were him in the Ritual, he couldn't have lasted much longer, for sustaining the Shadow Dragon primarily consumed the power of the Element of Spirit, and as a Slime on the Fallen Beast Path, Spirit was precisely his weakest element of the three.
This caused Ybur some distress, "It seems this Shadow Dragon Ritual isn't very suitable for me..."
Saraphido, now awake, said, "Not necessarily."