Adeptus Mandalore (Male reader x warhammer 40k)

yn novis is from a planet that the emperor wiped any knowledge of to protect a secret he kept even from his sons. their sister who is yn mother by blood and leader of the mandalorian people. though what happens when yn receives a destress signal from a nearby imperium system will he come to their aid and expose one of the emperor's greatest secrets or will he continue his people's isolation. for mandalore and the emperor!