Dahak

Dahak, the One Evil God, was the impulse of destruction, a powerful, ancient evil being and a recurring character on both Xena: Warrior Princess and Hercules: The Legendary Journeys. Although his true form has only been seen once or twice on-screen, he possessed Iolaus's dead body. He impregnated Gabrielle with Hope, his one daughter and representative on Earth. He was one of the main causes of the Rift and the events that later led to Gabrielle's apparent death.

Whilst in Brittania, Gabrielle grew close to a follower of Dahak, Krafstar. He spoke about Dahak in way that Xena and Gabrielle thought he referred the one God of the Israelites. Gabrielle soons discover that this Deity and his followers are part of a sinister and dark cult, devoted to unleashing evil onto the Earth. Gabrielle is tricked into killing a member of the cult and then impregnated with Hope, the bringer of Evil.

Dahak then attempts to release his army of evil onto the Earth, through Hope and Ares. He is then slowed down by Xena, who manages to kill the Destroyer, his grand-child, who kills Hope with it. Dahak may be the most powerful and dangerous of all the antagonists of both series.

Gabrielle's Impregnation
While Xena and Gabrielle are traveling they come across some guards taking some prisoners to Britannia for trial. As they passed them Xena heard one of the prisoners mentions that they will never give in to Caesar. Upon hearing Caesar's name Xena battles the guards and releases the prisoners. One of the prisoners named Krafstar, informs Xena that Caesar has captured their temple, as well as they have hired Boadicea, Xena's former ally, to help defeat Caesar.

Xena and Gabrielle travel to Britannia with Krafstar to help Boadicea. Gabrielle talks to Krafstar about his "one God" and seems to make a friend in him. Krafstar uses his friendship with Gabrielle to trick her into killing Meridian, as well as therefore, losing her blood innocence, which is what Dahak needs to be able to enter the physical realm. Xena sees strange dark clouds above the temple and fearing for Gabrielle's safety, she rushes to the temple. When Xena enters the temple she finds it deserted, with a dead woman laying on the alter. She sees Gabrielle crying in the corner and asks her who had done this and Gabrielle tells her that she had. Krafstar enters the temple, as well as him and Xena fight. The alter bursts open and flames grab Gabrielle, as well as dangles her in mid-air. Krafstar transforms into "The Deliverer". Xena Throws Krafstar into the flames and catches Gabrielle before she falls into the pit. Xena and Gabrielle take safety before the temple explodes. Dahak managed to impregnate Gabrielle before Krafstar defeat.

Hope
Gabrielle carried Dahak spawn for two weeks before giving birth to a daughter. Even though she is the seed of evil, Gabrielle tells Xena that because she is a part of her and that there must be some good in her as well: naming her Hope. Xena feared that Hope would be used as a pawn for Dahak, so Xena decides to kill her. Gabrielle, fearing safety for her child, sent Hope downstream in a basket, in secrecy from Xena.

Hope's Death
Eventually Xena and Gabrielle cross paths again with Hope, though due to her supernatural genealogy, she's already grown into a pre-teen.[4] Hope's manipulations cause Xena and Gabrielle to turn against each other, culminating in the death of Xena's son, Solan. Gabrielle eventually realizes Hope's true intentions and poisons her.The Dahak arc, however, continues over the Season 3 finale[5][6] to an early Season 4 episode where Hope finally meets her demise.[7] He planned on using Ares and Hope to sire a race of destroyers who would destroy the Earth and usher in his coming. However, both Hope and her child eventually meet their demise.

Possessing Iolaus
For a long while, Dahak battled against the gods of Sumeria who were able to keep him at bay. The battle caused chaos on Earth and King Gilgamesh used his palace to shelter his people. Gilgamesh blamed his father, Ra, for allowing his wife and child to be killed and secretly became a follower of Dahak. In order to weaken the gods, Gilgamesh drank the nectar that sustained them from the Chalice of the Gods. The gods were then weakened enough to allow Dahak to enter the world. The last step was the sacrifice of a "Warrior Heart." Gilgamesh intended to sacrifice his half-sister, Nebula, but Iolaus saved her life by sacrificing himself. In turn, Hercules killed Gilgamesh by throwing him into the fires of Dahak (HTLJ "Faith").

Dahak lured Iolaus' spirit into the realm where Dahak is still a prisoner and disguise his environment as the Elysian Fields. Taking on the form of Hercules, Dahak offered Iolaus "the power of a thousand gods" in order to liberate the Earth from the Olympian Deities' reign of terror. Iolaus had for a while refused Dahak's offer, but eventually gave into temptation by taking Dahak's hand. Dahak had finally entered the Earth in Iolaus' body with Iolaus' soul as a prisoner. The balance of light and darkness began to shift in Dahak's favor through every tragic event: The Sumerian deities have died as a result of having nothing to sustain themselves and Dahak himself had killed the noble druids of Ireland, who acted as mentors to Hercules after Iolaus' apparent death. Dahak had mentally tormented Nebula forcing Hercules and his new companion, Morrigan to return to Sumeria and confront Dahak now in possession of Iolaus' body. Dahak made a vague attempt to make Hercules believe that he is indeed Iolaus just with the power to achieve whatever he wants. Hercules, however refused to believe that he is Iolaus. Dahak easily escaped Hercules' grasp and journeyed to Greece. Hercules, accompanied by Nebula and Morrigan headed to Greece as well, to stop Dahak or die trying.

When Dahak arrived at Greece, he found that the Olympian Deities, who were severely weakened by his dark presence, had already left before his arrival. Dahak sensed that his former ally Ares had not left with them, instead choosing to hide. In spite of this, Dahak chose to adopt a disguise as Iolaus the new "god of light" in order to gain followers and trust of the people who believed that the Olympian Deities had abandoned them. He even made them believe that Hercules is the reason for the Deities departure, claiming he has returned to destroy them. Hercules wanted to know what Dahak had to gain from his deception and Dahak states the wants a return to the old days before the Olympians ruled the earth. Dahak was said to have been defeated by the Titans when he first manifested on Earth. This battle was said by Mnemosyne to have devastated the planet and left the Titans so weakened that Zeus was able to defeat them and claim mastery over the Earth. The extensive devastation also resulted in the Greek Deities rebuilding the planet into something more hospitable. Mnemosyne advised Hercules to gain the "stone of creation" in which its purest light will render Dahak powerless. After these revelations, Hercules gains a new ally, Zarathustra, who was once a follower of Dahak a thousand years prior to one of Dahak's attempts to enter the Earth. Zarathustra reveals that there are two basic forces that govern the universe: creation and destruction and that Dahak is the force of destruction. Zarathustra reveals to Hercules that Dahak wants Hercules to kill him in order to condemn Iolaus' soul to eternal doom, giving Dahak the means to plunge the planet into chaos. After obtaining the stone of creation, Hercules and Zarathustra confronted Dahak and bind him in chains using the stone to prevent Dahak's escape. Zarathustra begins a ritual to exorcise Dahak's being from Iolaus' body. Dahak taunts Zarathustra for killing his family and cursed him with immortality a thousand years ago in order to feed off of Zarathustra's anger and gain enough strength to kill him, preventing the ritual from continuing. Dahak revealed to Hercules of how he manipulated Iolaus into accepting him into his heart.

During this time, Dahak taunts Hercules further by telling him that Iolaus was nothing more than a travelling companion. Hercules tells Dahak that his friendship with Iolaus is one of the best things that he has been blessed with.[1] This moral sentiment upsets Dahak and weakens him enough for Iolaus to call out to Hercules from the spiritual realm Dahak has him trapped in. Hercules touches Iolaus' hand and is sucked into the spiritual realm where he sees his long dead friend. Dahak appears there too, in his true form: A huge crustacean-like monster. Hercules and Iolaus battle Dahak and send him into a fiery pit. With Dahak defeated and the balance of creation and destruction had returned to normal, Dahak's spirit was finally liberated from Iolaus' body. Zarathustra returns and guides Iolaus into an after life governed by the force of creation, which is later hinted at being the Judeo-Christian god.

Mythology and Possible Basis
Aži Dahāka or Dahāg is a three-headed dragon in Persian mythology. It appears in the Avesta, the earliest texts of Zoroastrianism.

Trivia
There are some contradictions within the series regarding Dahak. The chief druid tells Hercules that he is a creature from beyond this universe (or multiverse) implying he is from a different reality or dimension. Yet Dahak's recounting as well as that of the Titans suggests that he is a manifestation of the darkness within the universe (multiverse), which would indicate he is native to this universe (multiverse).

Xena: Warrior Princess

 * 1) "The Deliverer"
 * 2) "The Bitter Suite"
 * 3) "Sacrifice I"
 * 4) "Sacrifice II"

Hercules: The Legendary Journeys

 * 1) "Darkness Rising"
 * 2) "Let There Be Light"
 * 3) "Redemption"