The Sankofa Trilogy: Go back and fetch it.
VOLUME ONE
Destiny made them heirs to the world. Slavery made them warriors. Revenge will make them destroyers. In the ashes of a postapocalyptic Africa, twins Ras and Toomi are separated and sold into bondage. Their mission: protect Queen Maat and her kingdom from the patriarchal tyrants threatening to enslave their people. But first, they must escape slavery's grip and unravel the secret that will set them against each other in the ultimate battle to decide the fate of the new world. Sankofa One, Born Equal Only, Birth.
VOLUME TWO
Chosen to protect the ailing Queen Maat, twins Toomi and Ras now destroy what they were sworn to save. Leading legendary armies in the all-out wars of the kingdoms, they clash in a battle that decimates Axindar. With the queendom gone, a broken Maat flees through the wreckage, as her guardians threaten to bring down the world around them in a coil of vengeance, madness, and betrayal that will leave the world on the brink of collapse.
VOLUME THREE
War of the world's is coming. All that's left of the mighty Axindar kingdom are smoking ruins. As the tyrannical Acab and King Culumbra prepare to wipe out the last survivors of humanity, exiled Queen Maat holds the key to tapping a hidden well of power — if she can reunite her sworn guardians Toomi and Ras. But the twins, lost in a vengeful blood feud, must conquer their thirst for destruction and remember their sacred duty to protect their creator from the great evil rising to finish what it started.