Are you still reeling from the Once Upon A Time Season 4 finale? I am. In the blink of an eye, the very idea of a happy ending for the residents of Storybrooke went up in smoke — black smoke, in particular. Smoke that Emma Swan tethered to herself to save her former enemy and now closest ally, Regina. Now Emma is the new Dark One, her name etched indelibly into that infamous dagger, and it's anyone's guess as to what's going to happen during Season 5. I don't know about you, but I'm feeling all kinds of anxious about what's gonna go down, and how in the world they're going to save Emma before the darkness swallows her completely. It has to happen, though, right? (RIGHT?!)
We've got several months to find out how this whole "Emma as the Dark One" thing plays out, that gives us plenty of time to sit around racking our brains about what's going to happen not only to Emma, but to the people she loves (and especially the ones she doesn't). Normally I'd caution you not to let your imagination run wild, but given that we're talking about a land of fairy tale characters, I think you're safe to think outside the box. Emma tethered to such horrendous darkness can't possibly be a good thing, and I can think of a few things that might go down in Season 5 before we inevitably restore Emma to her former Savior self.
She goes on a self-destructive streak
Emma's always been a bit self-destructive, but the new weight of carrying all the universe's darkness within herself might just be too much for the Savior to bear. No doubt we're going to get some serious Emma angst in Season 5, and she'll probably do something really stupid and dangerous in a vain attempt to escape the darkness. It's gonna be SO GOOD.
She & Regina come to blows (again)
Emma and Regina pretty much come as a pair, now. They're inseparable and have an unbreakable bond not only as Henry's moms, but as close allies and friends. It's Emma that helped keep Regina on the path to redemption, and it's Regina who — up until recently — kept Emma from turning dark. Now that Emma's the Dark One because she sacrificed herself for Regina, no doubt Regina will want to be the one to restore her to her former self, and when darkness and light collide... the outcome might be a bit dodgy.
She tries to kill Zelena
Part of the reason Emma sacrificed herself was to preserve Regina's happiness, and if there's one person still standing in the way of that, it's Zelena. I'm not saying Emma's going to turn cold-blooded killer, but the darkness can do crazy things to you, and Zelena is pretty much pure evil. Sure, she's powerless at the moment with that anti-magic cuff on, but something's going to have to be done here.
She tries to kill Gold
The darkness was pulled from Gold to save his — and more particularly Rumpelstiltskin's — life, but with all the evil deeds he's performed in his life due to his role as the Dark One, Emma's likely going to think he deserves to be punished. She now has the means and the motivation to do so, and while it's unlikely Gold will actually die (we need Robert Carlyle in our lives/on our screens), she'll likely make a go of it.
She & Killian end their relationship
Sure, Rumpel and Belle made a go of things for a while, but I don't think being the Dark One is necessarily conducive to a happy and productive relationship, as we've seen. Emma may have turned a corner in telling Hook she loved him right before sacrificing herself for Regina's happiness (hmm...), but their happy ending together doesn't seem to be on the cards for Season 5.
Her anger at her parents rears its head again
Emma only recently made peace with Snow and Charming and all they'd done, from abandoning her as a child to, as she found out recently, cursing Maleficent's child Lily in order to make her the savior. Likely those still unresolved feelings are going to come right back around again, and this could prove dangerous for her parents.
She accidentally hurts Henry
Henry is the crux of what holds Emma together — and Regina together, and Emma & Regina together as a team, etc. — so of course the unfortunate situation when he's accidentally hurt by her darkness will happen. I'm not saying it's going to be fatal at all, but it might be a turning point in Emma as she struggles to contain the new blood flowing through her veins. Hold it together, Swan!