The Dark Wizard, first mentioned by Theos the War Phoenix on Newground Island, is his sworn enemy and many others as well as the main antagonist of Arcane Adventures.
Lore (Contains Spoilers)
Through the Arcane Chronicles, players are able to read about Durza's past, including how he gained his Absorption Curse and his motives as Arcane Adventures' main antagonist.
Durza was a boy with the inability to learn magic, distancing from the other village children who could. One day he stumbled upon a large, glowing, purple cube, and upon touching it he had gained the Absorption Curse, allowing the ability to absorb other people's magic and curses.
Three years later, Durza went stealing other's magics, after absorbing, he is able to control the source magics, and was dubbed "The Magic Thief." Soon after he received his infamous title, a man challenges him to a fight, in which he reveals that he is a Fire Curse user. After a long fight, the man had his physical energy drained and nothing more is said other than he had passed out.
Durza built a massive tower using his accumulated abilities, to study more about magic. Through his studies, he learned Dead Revival magic, undoing and combining curses, and mutate magic. From years of solitude, his title "The Magic Thief" was renounced. As the world advances, people soon discovers mutations as well, but Durza did not want his research to be interrupted, and decides to wait before stealing mutations.
After ending his solitude, Durza leaves his tower and begins magic-stealing again, absorbing Flash and Sun magic. He soon arrives at Aberon, where the Phoenix magic user, Theos the War Phoenix, guards the entrance. Durza attempted to absorb his magic to no avail, the battle between the two ended in a draw, Theos retreating into the city, and Durza, overwhelmed by his power, turned the other way.
Determined to defeat him, he used his Dead Revival magic to assemble an army of undead villagers and wizards, with magic being provided by Durza, and ordered his army to hunt down Theos. The majority of his army had been easily vanquished by Theos. Furious, Durza went to engage in battle with him once more, destroying villages and forests in the process.
Only once the fight started, he knew it was imminent that he would lose the battle, having lost a leg to the Theos' Phoenix magic. Desperately, he combined all of his accumulated power he has gained and launched it toward Theos in one massive attack. It was said this attack had missed, hurling to the ground, splitting lands apart into small islands and massacring 80% of the human race.
After the near extinction from the attack, Durza began to rebuild his undead army, supposedly located at a large, dark forest island. Durza ditched his physical body and traveled around as an immortal dark spirit, continuously absorbing more curses and magics, even during the adventures of the player.
Being the Phoenix user he had fought, it is obvious Durza and Theos are archenemies. While Durza had little initiative towards battling Theos once more, Theos had made the existence of the Dark Wizard publicized, gaining followers who desire to annihilate Durza once and for all.
Durza despises the A.G, as he wanted to rule the world, but the A.G had beaten him to it. In revenge, he resurrects sunken ships, of which are unsinkable, and puts his undead armies on board of these ships.