Fantasy: My Spiritual Beast Is an Egg?

The young master of the Long family in the frontier fortress, the awakened spiritual beast is actually an egg? The hatch is actually an all-powerful mythical beast, and the protagonist wants to worship it as his master? The indifferent senior sister is actually a jealous little expert, and the twin lolita are little troublemaking geniuses? Is there moral decay or the author's unscrupulousness behind all these stories? PS: This is a romance novel wrapped in fantasy. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.