Dagon's History
Dagon is an extra-dimensional demonic entity who tried to invade this dimension with the help of his Lucubra army during Earth's medieval era. He was banished back to his dimension when Sir George defeated him by cutting out his heart with Ascalon, a powerful weapon given to him by Azmuth nearly one thousand years ago.
In The Flame Keepers' Circle, Dagon was first introduced as a legendary alien god who is believed to have visited Earth many years ago and brought advanced technology to humans in the past. He is also believed to have sworn to come back to Earth to bring the "Golden Age". He claimed he would bring alien technology so that Earth will not have war, nor disease, just peace. His appearance was revealed in a carving.
In A Knight to Remember, Dagon took control of Gwen and explains to them that if Vilgax gets his heart, he will be able to take control of the entire universe. After Vilgax defeats the Forever Knights and the Esoterica, Dagon takes control of Winston and tells him that in order to be powerful enough to rule the universe, he must break the seal. However, this was a trick.
In Solitary Alignment, his shadow was seen in a flashback. Azmuth also notes that Dagon has enslaved 100 dimensions at the time.
Dagon's voice was heard in Enemy of My Frenemy, being called by the name Old One, a being who can bring dead people back to life. Charmcaster gave him six hundred thousand souls (from every living thing in Ledgerdomain except herself) and in return, asked to bring her father back to life. Spellbinder disapproves of this, saying that his daughter became a worse tyrant than Addwaitya ever was by doing so. Spellbinder says that even though he loves her, he can't stay in Ledgerdomain with her, knowing that his life was bought by the cost of so many others, and decides to leave again. He returns to the dead and the Dagon makes all the souls return to their bodies, saying that "such is the way of magic".
In The Beginning of the End, Dagon's voice was heard again when Sir George demanded to face him, but Dagon instead summoned his herald, Vilgax.
In The Ultimate Enemy: Part 1, Dagon was able to turn every human into an Esoterica except for Ben's Team, Julie, and Sir George. Later, he took control of Gwen again and he tried to use her to break the seal. Eventually, he broke the seal himself, thus allowing him to enter Earth's dimension.
In The Ultimate Enemy: Part 2, after Dagon freed himself, Sir George immediately attacks him. Dagon then ordered his herald Vilgax to destroy Sir George, but he is nowhere to be found, and thus Dagon sends his Esoterica to defeat George. While Gwen, Kevin, and George fight a couple of Esoterica, Ben transforms into Way Big, and Way Big transforms into Ultimate Way Big. Dagon fights Ultimate Way Big and easily defeats him with acid rain, with none of Ultimate Way Big's attacks having an effect on him. He then proceeds to fight Sir George and Chromastone. After he defeats Chromastone and kills Sir George, Vilgax and Psyphon return with their machine. Thinking it was a weapon, Dagon used his laser beams on it; however the machine absorbs powers from other living beings and due to Dagon's essence being only power, he was fully absorbed within the machine. Psyphon fired the machine at Vilgax and he received all of Dagon's power.
At the end of the battle, Ben used Ascalon to defeat Vilgax by absorbing Dagon into it.
