Kenapa Supreme King Dragon Starving Venom Forbidden di Yu-Gi-Oh!?

Supreme King Dragon Starving Venom can copy the effects of monsters on the field and in the GY. What effect does it copy that made this card banned in the TCG? Let's discuss and discuss in the comments~ Music: 1. HeatleyBros "Egypt Desert Mystery!" 2. Doug Maxwell "Gangsta Choir Descends"