WARNING: The following article contains spoilers for Justice League: No Justice #3 by Scott Snyder, James Tynion IV, Josh Williamson, Riley Rossmo and Marcus To, in stores now.
In order to save the universe in Justice League: No Justice, Brainiac kidnapped the gratest heroes from Earth. To everyone's surprise, he also brought along several villains to the party. While the likes of Lobo, Deathstroke, and Lex Luthor have more ambiguous natures than most, only Sinestro and Starro appear to be the true villains included on the mission. In issue #3, it's Starro who proves himself to be a true hero, even if it results in him making the ultimate sacrifice.
Since his reappearance in Dark Nights: Metal, Starro has been a character who is actually capable of advanced reasoning. Typically the Star Conqueror has been presented as more parasitic life form than action hero, but Scott Snyder's version of the character is a sarcastic, arrogant and petty bully. He is capable of telepathic speech, which he constantly uses to insult those around him. It is this quality that allows him to be convinced to change his nature and do the right thing.
The Making of a True Hero
Considered an alien entity who embraces the cosmic energy of mystery, Starro was placed on Team Mystery alongside Martian Manhunter, Superman, Starfire, and Sinestro. Two telepathic members on the same team may feel like a redundancy, but it is clear that Brainiac had planned for this. It turns out the villain had an ulterior motive for gathering these teams, and the technology in their suits actually works to inhibit some of their powers. This means Martian Manhunter telepathy has been weakened, but it seems Starro's work just fine.
In order to ignite the Tree of Mystery, Team Mystery realizes they must release thousands of miniaturized planets from Colu's Nursery. To do it, they will need a telepath who can help the residents of these planets survive the process of enlargement. Without Martian Manhunter's abilities, that responsibility must fall to Starro, though the giant starfish isn't exactly convinced of the idea at first.
The issue opens with J'onn J'onzz discussing their predicament with the Star Conqueror. Known only as a tyrant until now, Martian Manhunter asks him if it is "possible for [him] to be something greater." Brainiac may have included him on the team because he knew Starro was a villain, but that doesn't mean he can't rise up to become something more. When Starfire discovers that her home planet of Tamaran is among the planets in storage, her pleading finally gets him to step up. Instead of using his abilities to "enslave weak minds," he reaches out to billions of alien life forms to calm them and tell them it will be all ok. This allows Sinestro to guide the expanding planets safely into outer space, thus officially introducing the promised new sector of the DCU to be explored in Justice League: Odyssey.