Higher or White Knights were beings from the Aether that served a god or goddess.
Higher Knights[]
Each higher knight originated from the Aether and served any god or goddess from any mythology. Examples of these gods or godesses are the Creator, Satan, Kratos, Athena, Zeus, Poseidon, Thoth, Ra, and many many more. Basically, any mythology has a god that was manifested throuugh the peoples belief primarily in the Aetheric realm. But entities like Satan would be most likely found in the Nether/Hell. They were formless under their armour.
Purpose[]
The White Knights (the knights from the Aether) were sent out to kill demons. But, if the demon was worthy, it would be purified and would go through a re-ascension process where it would get another chance at being a Holy entity.
Reincarnations[]
When a Higher Knight was reincarnated into a physical form, it would take after whatever the god or goddess was representing. For example, if you were reincarnated from being a White Knight that served the goddess Athena, you would take after one of her traits which could be a mastery at crafts or you could have a lot of wisdom/be very knowledgeable.
~Informative perspective given by ImAMonkey