WARNING: The following contains spoilers for the first six episodes of Young Justice: Phantoms, streaming now on HBO Max.
One of the most shocking aspects of Young Justice: Phantoms is how the series killed Superboy on Mars as the race war played out. It left M'gann (aka Miss Martian) shattered as she lost her husband, with the death reverberating on Earth with Artemis and Superboy's former colleagues. However, as M'gann tries to piece her life back together, she gets a new partner and a ray of hope.
M'gann and J'onn J'onnz are trying to decipher who'd want Conner dead in "The Lady, or the Tigress?," as the gene bomb had kryptonite. J'onn contacts Hawkgirl but all the cosmos' kryptonite is accounted for, which means there are sources out there the Justice League can't track. It has the Martian Manhunter stumped, made even worse when M'gann finds the perp behind the attacks: her brother, M'comm.
He admits he was just following orders from a mysterious source as she pummels his radical group. She ends up reading his mind, only to realize he's telling the truth. After the deceptive extremists are apprehended, Miss Martian's back to square one and heads to Earth with no closure. But as she's leaving, her sister, M'ree, joins her.
M'gann's despondent, agreeing without any real enthusiasm, but M'ree wants to be there and help her sister heal. They had so many differences in the past due to their skin color, but M'ree understands her identity better as a Green Martian, aiming to care for her sister, a White Martian. After they resolved things, training with M'gann will help M'ree hone her powers too, as M'gann's a pretty badass soldier, which would ultimately teach her about humanity.
It's made her sister a better person, so M'ree wants to experience that. Given that uncle J'onn is there to mentor her too, it's a win-win. By helping M'gann cope, she'll level up into a better hero, which J'onn has no problem with. As they bid their parents goodbye, though, the older heads hope this isn't the last they see of their girls. M'gann has already hinted she doesn't want to come back to the planet that took her beloved, but M'ree can help remind her not all is lost.
M'ree herself was ashamed of being Green instead of Red, hating on White aliens too, but she's slowly growing and maturing. Thus, once M'gann truly grasps how far she's come and how much potential she has, we can see Miss Martian letting the past and all the politics go, while remembering at the end of the day, there will always be light and dark.
Helping M'ree can be M'gann's new purpose, reiterating that she doesn't have to neglect her family. Her brother may have gone off the rails but her parents and other siblings shouldn't suffer for his sins, which is something an inspired M'ree is already trying to impart.
To see how Miss Martian's sister joins her rehabilitation, the first six episodes of Young Justice: Phantoms are streaming on HBO Max.