So, I keep seeing some takes on Em and Merc that seem to me as good victim and bad victim and I am scared this is where their story is going!
Fear not, young padawan! Jk. but honestly, don't worry, they aren't going there. If anything, Emercury's story has the potential--deliberate or unintentional--to deconstruct the concepts of "good vs bad victim."
So, what is good victim vs bad victim? Well, the concept of "good victim," while a colloquial term that might irk people, essentially points out a cultural reality: that people who respond in more societally acceptable ways to abuse (such as crying, feeling sad, even self-harming) are a lot more palatable. But people who respond to abuse in just as realistic, yet less societally acceptable ways (such as anger and lashing out) are a lot less palatable. To an extent, we can understand where this concept comes from--someone who is a "bad victim" is hurting others. But both are highly, highly realistic responses to abuse, because abuse doesn't usually make someone a better person.
Emerald fits the concept of "good victim" a lot more clearly than Mercury does. She's more emotional, she bonds more easily with people, she is able-bodied (has a powerful semblance), and she was always set up to be redeemed first.
Mercury, however, has many of the intrinsic "bad victim" traits: he's colder, he doesn't easily bond with people, and he's not able-bodied (yeah, look at fiction and how that tends to play out. It's a trope that is very common and ableist). However, I think the point is that Merc is very much framed as a victim.
Emerald grew up as a child abandoned by society. She's a victim of society who starts her redemption by helping an entire society (Atlas and Mantle) escape annihilation. Along these lines, it also makes sense she's able to bond with anyone who shows her kindness--society rejects her in her childhood, so she must be accepted by groups and society to heal. In alchemical terms, she's the macrocosm.
In contrast, Mercury is more of a microcosm. His trauma and his healing are found in one or two bonds with individuals. At first, his wounding came from his father, who abused, tortured, and stole his literal soul from him. Then it's Emerald and Cinder, and now Tyrian and Emerald. Mercury's bond with Emerald, however, should be what saves him--and he should redeem himself with something related to either Emerald or Cinder (not saving Cinder, but quite possibly confronting her and telling her off). When Mercury joins team RWBYJNORE, it'll probably be less him actually caring about doing the right thing and a lot more about him just caring about protecting Emerald.
So those are my predictions, and the differences in how their arcs/character roles are structured. But how is Mercury potentially a bad victim deconstruction?
Well, because of the two of them--Emerald and Mercury--the one who is constantly protecting the other is Mercury. That's something you'd expect of a good victim (there are some moments of Em doing this, but it's mostly Mercury). It's subtle but there from Emercury's very first appearance. Mercury:
At the fight at Tukson, Tukson lunges at Emerald. Mercury is then the one shown kicking him.
Mercury begs Emerald to flee with them when she realizes Cinder failed in Haven.
Mercury tells off Tyrian when he threatens Emerald in season 6: "back off, freak!"
Despite his coldness when Emerald asks why he came with Cinder and her, Mercury does open up to her and tell her exactly why he went with them, and tries to give her his own (albeit warped) advice, because his advice is how he's survived thus far. "Cinder doesn't care about you. She doesn't care about any of us..." Before delving into what he talks about his father. He clearly projects his feelings for his father onto Cinder, and is advising Emerald to do what she can to survive, like he always has.
In season 8, he warns Emerald from following Cinder around because he is worried for Emerald: "She went against our queen. I'd be careful who you back... would you stop trying to protect her already? She doesn't care about you!" Mercury gains nothing by telling Emerald not to care herself about Cinder--unless he cares himself for Emerald.
In the departure scene of Season 8, Mercury also tells Emerald the truth about why he's there: he's afraid, and he doesn't want to die fighting against Salem: "[Hazel's] not gonna pick fights be can't win. Neither should we." Note the "we."
I wouldn't be surprised in Team RWBYJNR are less willing to forgive Mercury than Emerald. Mercury has even more personal history with Yang, and of course, Mercury never bonded with them how Emerald did (even if Emerald said she was only acting, she clearly was not). I'm intrigued to potentially see this become a source of conflict in the story--because Emerald will surely want to save Mercury, while I am betting the others will understandably have doubts. There are a lot of potential themes that could be developed there.
Anyways, if they are going to save Cinder (even if I do think redemptive death is her likely ending), there's no way they can do that without saving someone who was a victim of her abuse, not in a YA show.
