Mahad, Atem, and Mana are not related to each other at all. They were raised in different hierarchies of their country, yet they still ended up in the same palace and became friends.
This is only my headcanon, and I have made Mahad the child of a former slave who was freed. This meant he had no house or rank to his name. he wouldn't have become anything other than a servant for the royal family or a farmer if not for him and his mother being close to the royal family. It is why Mahad takes his duty as Atem's servant and priest so seriously. He owes everything to his former pharaoh for giving him a chance to become a priest with nothing to his name.
Mana is the child of a high-ranking woman(in my headcanon, a former courtesan to Aknamkanon, but Mana is not his) and a soldier. She was born and raised in the palace, but she is not part of the royal family by blood. With her having such a high rank and childhood friends with Atem, she is almost untouchable, and she knows it. She was picked to be a corcubine for Atem when he came of age, but Atem never touched her since he couldn't get himself to take her dream of becoming a mage from her. But her title as Atem Corcubine made her even more untouchable to some of the palace staff annoyance. Mana is a bit of a menace.
Atem is, of course, the future pharaoh and the last child of the royal couple. He used to have older siblings, but they all died before Atem was born, meaning Atem was trained almost right away to become a pharaoh. That meant he wasn't allowed to be reckless, so he didn't have many friends growing up. The only friends he had were Mana and Mahad, who were the closest thing Atem ever had to siblings. Both of them decided to follow him through time and space to find him, even if he didn't remember them. Their loyalty to him was too great to make that stop them.
