Akiva is a seraph. As a bastard son of Emperor Joram, he is a member of the seraph army faction known as the Misbegotten. He has an unusually large capacity for magic, possibly due to his mother's Stelian ethnicity.
Akiva is described as supernaturally beautiful. His face possesses attractively high cheekbones. He is amazingly tall, with extremely muscular arms and skin that is honey in color. He has short dark hair. White scars run across his lean, callused hands, while his fingers are tattooed with black lines that mark each chimaera he has killed in battle. Like all seraphim, he is very attractive. His wings are fire and able to be hidden - though they will still appear in his shadow. Akiva's beautiful golden-amber eyes, framed with dark and heavy eyelashes with kohl around his eye parts, are fire-like and majestic as well.
Akiva is intelligent, having taught himself magic and hidden it from most except for his two closest siblings and Madrigal, his lover. A visionary, he dreams of a peaceful world where chimaera and angels can live together in harmony.
In the midst of the war between the seraphim and the chimaera, Akiva was born to Joram, the seraph emperor, and a Stelian concubine named Festival. Although his mother remains an unfamiliar figure to him, he did grow up with half-brother Hazael and half-sister Liraz. At five years of age, he and his two half-siblings were given over to train as soldiers. They stayed together, always fighting along side each other and carrying out the same missions in a world at war. At some point, Akiva learned the chimaera's language, or at least "enough of [it] to give orders to slaves". But something would occur at the battle of Bullfinch that would change his life and shatter his preconceptions about the chimaera. This particular battle inflicted grave injuries on him, and he was sure that he was going to die when a certain chimaera knelt next his body...and applied a tourniquet to his wound. This certain chimaera being his future lover Madrigal.
Akiva is first seen in the Saudi Arabian city of Riyadh, burning a doorway to Brimstone's workshop. He then flies towards another city in his quest to destroy all of the portals in the human world that lead to the shop. He follows Karou out of the shop. He is shocked because this girl appears to be human. She reminds him of his lover Madrigal. He later finds out that Madrigal is Karou.
Akiva is separated from Karou after she is devastated by the discovery that he is the cause of Brimstone's death. Akiva returns to Hazael and Liraz, and they gradually begin to agree with his idea of peace in Eretz. Akiva secretly aids the chimaera and kills Joram, but finds out that he has only been playing a part in Jael's game. After the Dominion, Jael's troop killed Hazael, Akiva let out a scream that exploded the Sword, and damaged the veil. Jael takes over the kingdom and sends the angels to the human world to gain support and ammunition. Akiva and Karou are forced to unite their armies, and the rest remains to be seen.
When Jael travels to the human world in search of weapons of mass destruction, Akiva and Karou must unite their armies. Though the chimera and seraphim are united it is far from what the two had once dreamed of. Over time Karou learns to forgive Akiva and the armies must begin to respect each other regardless of their past. The rebellion has a plan but all goes south when the Dominion army locates their base. Regardless, Akiva and Karou must find Jael and carry out the mission. The two expect the worst when they return as they were largely outnumbered. Just as things are looking up for Akiva and Karou, Akiva discovers that he has been draining the veil, a mighty power source that has kept all the worlds safe from monsters and large as worlds, Nithilam. The two must separate again.
They have a relationship which began when Karou, as Madrigal, rescues him from certain death by winching a torniquet for his bleeding arm and leading her troops away from him. Akiva never forgets this deed and it fuels his motivation to learn the chimaera language and magic. He sneaks into the chimaera's holding and dances with Madrigal, whom Thiago lusts after, and reveals his identity. He shocks her but nonetheless ignites the start of their romance.
Both of them have an instant affinity with each other, as Akiva manages to find Madrigal even when she is reborn as Karou, and Karou is able to "sense" Akiva's presence or absence. This is likely due to “fate”.
The relationship is, however, complicated by the war, as Madrigal is a soldier for the chimaera and Akiva is a Misbegotten, one of the many bastards fathered by the seraph emperor to be trained as tools for war from a tender age of five. They are lovers trapped at the opposite sides of war, but being madly in love, they dream of a world of peace, where angels and chimaera live together with harmony. The two meet at Ellai's temple every night to spend time with each other.
Just when they are plotting to kill the war leaders to set their vision in motion, they are captured by the chimaera, and it is later revealed that Chiro, Madrigal's sister, had betrayed her to gain Thiago's approval.
Akiva is tortured, and made to watch as Madrigal is beheaded and evanesced - or so he thought. In actuality, Madrigal's soul had, under Brimstone's instruction, slipped into Chiro's body and taken possession of it. With Chiro's body, she frees Akiva, who is mad with grief, and makes plans to avenge her.
Having gleaned the chimaera's secret of resurrection from Thiago during his torture, he is instrumental in helping the angels win the war and resulting in the deaths of thousands of chimaera, including Brimstone and Thiago's father, the then-Warlord. He earns the title "Beast's Bane" and "Prince Bastard," and a newfound respect among the angels.
Having been hardened by his devastation of losing Madrigal, he reverts into his former self - until he found Karou and her wishbone, and realizes that Madrigal is still alive in her, and more significantly, that he has indirectly killed her whole family.
When they break the wishbone and Karou learns the truth, she refuses to have anything to do with Akiva. In Days of Blood and Starlight, their romance is scarce. Akiva tries to atone for his mistake by saving civilian chimaera, rescuing Ziri, returning Issa's soul and even killing Joram, but nothing seems enough to compensate for the horror of her lost family. Karou still harbours feelings for Akiva, but feels ashamed and guilty by it, especially around other chimaera, led by Thiago, who constantly reminds her of her status as a traitor.
They reach a truce when the angels, led by Jael, who has gleaned information of powerful human weapons from Razgut, enter the human world to try and gain their support. The rebel angels and the chimaera soldiers unite reluctantly, with Akiva and Karou now on the same team.
- Madrigal was Akiva's former lover. She was a chimaera. When they met in Bullfinch, Madrigal saved Akiva's life. Then she left him on the beach. Madrigal was betrothed to Thiago, the White Wolf. However, Akiva found her at The Warlord's ball, and the two fell passionately in love with each other. Akiva snuck Madrigal out of the masquerade and then proceeded to spend the night with her. When they were caught one day, because of Madrigal's foster sister Chiro, Madrigal was sentenced to be executed for loving the enemy, and Akiva was forced to watch. Madrigal was beheaded, but later returns to the world as Karou. Though she doesn't have her chimaera aspects, Madrigal's soul is Karou.
Hazael is Akiva's half-brother. He is also very attractive and a dreamer, child-like, cheerful and very easy-going.
Liraz is Akiva's half-sister. He loves her too much and is very protective of her, especially after Hazael dies. She is fierce and tough.
Joram is Akiva's biological father. Despite this, Akiva does not regard him as a true father, having been trained from birth as a soldier and pawn in Joram's war against the chimaera. He is only one of Joram's numerous bastards.
Festival was Akiva's mother. He knows little about her, other than her name and Stelian heritage. In Days of Blood and Starlight, however, he remembers her last words telling him to be strong as he is taken away from her. This memory is hinted to have helped him unleash an unusual amount of magic that helped him and Liraz escape from Jael's grasp. It is possible that Akiva inherited his magic from his mother.
- "Long life is a burden, when it's spent in misery." - pg. 206
- "I didn't know. If I'd known, Karou, I would have believed in redemption..." - pg. 456
- "Your soul sings to mine. My soul is yours, and it always will be, in any world." - pg. 303
- “What can a soldier do when mercy is treason, and he is alone in it?”
- “As long as he had life, who deserved it so little, he would use it, wield it, and do whatever he could in its name, even if it was not, was never, enough”
- “Soon, everything else would come rushing at him. Like the ground to a falling man, it would come rushing up and hit him all at once - the place, the company, her words; one implication would lead to another and shatter him - but around that intake of breath the world hung silent and bright, so bright, and Akiva only knew this one thing, and held on to it and wanted to live inside of it and stay there forever.
- Karou was alive.
- "Who knows better than I? You betray everything you believe in. You drown your grief in vengeance. You kill and keep killing until there is no one left."
- "It was not a happy ending, but a happy middle-at last, after so many fraught beginnings"