Complex sentence: Nightstar is a fictional character, the daughter of Red Robin (Dick Grayson, also known as Nightwing, the first Robin) and Starfire from the "Kingdom Come" and "The Kingdom" comic book miniseries by DC Comics.
Split into simpler sentences: Nightstar is a fictional character, the daughter of Starfire and Red Robin aka Dick Grayson, who was also the first Robin and Nightwing. Nightstar features in "Kingdom Come" and "The Kingdom" comic book miniseries by DC Comics.