It might be a stretch, but it's possible that Dilton himself is the Gargoyle King, and that he pretended to be one of the victims. One major clue about this theory is an Instagram post Roberto Aguirre-Sacasa shared. He captioned a photo of Dilton, "'D' is for Dilton. Demented, deranged, diabolical, but also...possibly...demonic?" That could be a red herring, but it could also be a clue.