Where does Jesus get his humanity?
There is something missing in your assessment of Jesus' humanity.
Most people assume that Jesus was immortal in heaven before his human birth, but the truth is no other being in existence possessed immortality except God himself originally.
Consider that the Creator had spirit beings in heaven ordered into rank and file. None of these spirit beings are immortal, even though they have no "natural" cause of death. "Mortal" means you can die......immortal means that you cannot go out of existence, from any cause.
The fact that both wicked angels and humans can be executed is proof that they are not immortal.
There is a difference between everlasting life and immortality.....something most people never consider.
Humans are a "lower" creation than angels but neither were given "the power of an indestructible life". How foolish would God be to create powerful creatures with free will and not be able to implement the death penalty if they abused it.
The devil has a destiny and he knows it...he and his hordes will end up in "the lake of fire" but this is not "hell"...it is a symbol of the "second death". Unlike the death we humans experience as a result of Adam's sin, this is a death from which there is no resurrection. Whoever goes into this symbolic place, will never be seen again.
The fact that some angels featured more prominently in the Bible record is interesting. Only two angels are named in scripture....Michael and Gabriel. Out of the millions of angels that the Bible says exist, why do you think only these two are named?
An angel who appeared to Manoah was asked for his name and he refused to give it. (Judges 13:15-18) Why? Humans have the propensity to idolise those they consider to be "gods" and who can be of service to them in some way. Angel worship is alive and well in this world as we speak.
Faithful angels have the ability to materialise human bodies, as the Bible indicates, but "the Word" who was "with God" in heaven, did not come to earth as a materialised being...why? Because part of his credentials as Messiah required that he fulfilled prophesy, an important part of his proof of identity meant that he had to be born of a human woman (a maiden) in a certain family line, in a small town called Bethlehem. He arrived, right on time as the scriptures said.
Where did Jesus get his humanity? From the operation of God's holy spirit in transferring the life force of his most trusted servant to the womb of the woman he chose to be his early mother.
The child was thus human in every respect. He was not God because God is immortal. Since an immortal being cannot die, Jesus could not have been God...his death would have been a ruse.
As a reward for their faithful service, God granted his son and those chosen to rule with him, an immortal life in heaven. Faithfulness and obedience to death is the requirement for being granted immortality....but only for these chosen ones.
The rest of obedient humanity will stay right here on earth under their rulership and all will return to God's original purpose as stated in Eden.