DemiDevimon is Myotismon's lackey. He is a trickster and a liar, attempting to deceive the kids whenever possible. Although a force of evil, he knows to run and cower when he is outmatched. He caused a lot of trouble for the Digidestined, such as making Sora think her crest wouldn't work, getting Joe lost, and making T.K. think Matt didn't like him anymore.  Demidevimon is very loyal to Myotismon. He would do anything Myotismon would tell him and even helped him when things seemed lost. In the episode "The Prophesy", Myotismon digivolved into Venom-Myotismon and needed energy (food) so Demidevimon let himself be eaten by Venom-Myotismon.