As mentioned by several characters, Astroth is seemingly ageless. He possesses pale almost white skin and black eyes and he is always smiling. He has long, black hair which falls past his shoulders and usually wears white robes. During his visit with Max however, he wore pitch black robes.
Astaroth is one of the most charming and charismatic characters in the series. He is extremely intelligent and understands things that no human could dream of understanding. He thinks of himself as a living god. He is cruel as well, but also has a playful side, and has a sense of chivalry and a good sense of humor. One of his most defining characteristics is the fact that he does not lie. He is also arrogant, unable to help himself from consuming David's poison in an attempt to show his superiority.
In The Maelstrom, it is insinuated that he is from another universe. In The Red Winter, it is revealed that he is not a demon at all, but rather a unique being created by entities called Starving Gods to find them another universe to feed on. Astaroth fled from the dying universe in which he was created and arrived on Earth about 10,000 years prior to The Hound of Rowan. At an unknown point, he decided he wanted to be the Creator God of this new universe and began seeking the Book of Thoth for this purpose.
The Hound of RowanEdit
He was hidden in The Sacrifice of Isaac, a painting by Rembrandt Harmenszoon van Rijn in 1635.
The Second SiegeEdit
Astaroth begins to topple governments throughout the world after he is released. In a meeting between Rowan, the Workshop, the Witches, and various nations, it is revealed that over sixty governments were on the cusp of falling. He followed Max and David during their journey to find the Book of Thoth. This led him to the Workshop, where Bram's Key was located. Astaroth is summoned by David to grant him three requests after he and the others return to Rowan. When he is summoned, David's friends unexpectedly follow him. This causes David to use one request on Cynthia Gilley, who Astaroth promises to never hurt again. David then asks him how to use Bram's Key. The last request is made by Max, who asks what happened to his mother. Astaroth answers both questions, then disappears until he is seen in the Sidh, where he confronted the duo, demanding that they give him the recently recovered Book of Thoth. Instead, Max impales him with the Spear of Lugh. After Max, David, and Deirdre Fallow escaped to Rowan, Astaroth sent Aamon to negotiate for the Book. He tried to obtain the Book by using Mr. Sikes to possess Connor Lynch. When both of these attempts failed, Astaroth sent his army to take the Book by force. The army was held off temporarily by Max and Cooper, but Rowan was eventually forced to relinquish the Book. Astaroth and his army then left Rowan.
The Fiend and the ForgeEdit
Astaroth begins to change the world using the Book of Thoth. He awakens many magical creatures and attempts to make his own, though these are largely considered failures. He sends Prusias to present his Five Edicts to Rowan. He is largely unseen until he visits a captive Max in Prusias' prison. While there, he interrogates Max and learns of David's plot to poison the demons at Walpurgisnacht. When he arrives at Walpurgisnacht, Astaroth reveals that David, Max, and Toby. He forces Mad'raast to consume the blood petal poison as an example to those assembled. However, he then consumes one of the flasks in order to prove his invulnerability and is tricked into releasing Elias Bram. Due to his public shaming, he vanishes and is no longer considered to be the Great God or ruler of the demons.
During the Maelstrom, Astaroth is largely absent. This is mainly in order to avoid Bram, who is hunting him. He is spoken of by Bram, who reveals that Astaroth is in fact not a demon. Before Rowan's battle with Prusias, Astaroth appears to Max, promising that he will save Rowan from Prusias if Max will kill Bram. He appears to Max again after the dreadnoughts are released, coaxing Max to summon him. However, Max is stopped before he can do this by the sudden appearance of David, and Astaroth disappears.
The Red WinterEdit
Bram continues his hunt for Astaroth, although is later revealed that Astaroth is instead hunting him. It is revealed that Mr. Sikes was once the human Neheb and that he was turned into an imp by Astaroth. While David is shadow walking to the Isle of Man, he is caught by Astaroth, who gives David back his hand. After Rowan defeats Prusias, Astaroth is seen in the streets of Blys. He incinerates five hundred soldiers, creating monsters, most notably a dragon, from their ashes. This prompts Max and Bram to journey to Tartarus in order to find and question Neheb. This turns out to be a trap laid by Astaroth, who kidnaps Bram. Without the sorcerer to challenge him, Astaroth uses the Book of Thoth to turn Rowan into an island. He travels to Ymir, a place where the barrier between worlds is thin, in order to create a portal for his masters, the Starving Gods. He succeeds in opening the portal, but is injured by YaYa and killed by Max. His attempt to bring the Starving Gods into Earth's universe is foiled by David, who closes the portal.
Astaroth is an ancient being of prodigious magical might, and is easily one of the series' most powerful characters.
Shapechanging: Astaroth may alter his shape at will into any form he desires.
Devour: Astaroth can consume other magical beings to gain their power, as he did with Elias Bram.
Shadow Walking: Astaroth can enter and leave Nether at will. He suffers no negative effects while there, unlike other travelers.
Durability: Astaroth is extremely tough; YaYa's horn broke against his side.
Magic: Astaroth is capable of widely varied spellcasting, including on a large scale (e.g. summoning storms with the book on large scale)
Book of Thoth: After acquiring the Book of Thoth, it becomes Astaroth's most powerful and useful ability. He can blur, erase, alter and combine any truenames he chooses, effectively giving him the power to alter reality to his whims; only things with truenames tied to somewhere else are immune. His only limitation is that he cannot truly create, as he is from another universe; anything he tries to create is horribly misshapen, although he can still create very powerful beings this way. While he tends to use the Book on a global scale, he has shown the ability to use it in combat, on one occasion burning hundreds of soldiers to ashes with it and creating monsters from their remains.
Geis: Astaroth is unable to lie, as limitation placed upon him by Lugh when Astaroth visited the Sidh in pursuit of Bram and the Book of Thoth. To break his geis would cause him to forfeit his immortality. This also extends to any promises he makes, so he is unable to harm Cynthia.
- (To Max) "He does not love you, Max McDaniels. You frighten him.... Bram knows there will be a day when he cannot stand against you. Given the man's past, do you really believe he will let that day come?"