One is biological,
The other one is also biological.
Before he died, the leader of the alliance took his youngest son's hand and said, from now on, you must restrain your temper and assist your brother in upholding justice.
The younger son nodded and said: Dad, I understand.
The alliance leader took the eldest son's hand again and said, although your brother is perverse, he is not incorrigible. You must love him more and let him establish himself in the world and be worthy of me...
The leader died before he finished speaking.
The eldest son thought for a moment and burst into tears.
Dad, why are you walking so fast! You haven't officially passed on the position of heir to the alliance leader to me yet...