@Nah Someone spoiled their nature in relation to MC some chapters back.
Spoiler!
They are pieces of MC that he lost when he was brought down to human and incarnated as such. He doesn't remember them or that he was once a g**.
The Galactic Navy Officer Becomes an Adventurer
by Takuma Tomomasa , A_Itoh
Available on mangabuddy for reading, and for sale at https://www.amazon.com/dp/B0BT6V7CMM
by Takuma Tomomasa , A_Itoh
Available on mangabuddy for reading, and for sale at https://www.amazon.com/dp/B0BT6V7CMM