Sombra's POV:
I hear a ping come from the necklace. I touch my horn to it to track it. It comes up with a location under the frozen ground of the tundra around the Crystal Empire. I don't bother to grab Twilight and all of her friends, I just go. If it means giving my girls back their mother, I will do it alone and fast. As I appear in the doorway to the bunker that has been built to imprison my girls' mother. I realize that I need Twilight and her friends to take on whoever is holding her hostage. I teleport all of them to my location.
"What in the hay is goin' on here?"
"I need your help to rescue Styx, she has been missing and her tracking necklace finally just pinged. This is her location, and I need your help to take down whoever is holding her prisoner."
"Of course, Styx is our friend and we need to save her. She is a vital part of Equestria." Twilight says, rallying her friends behind her.
Twilight, Starlight, and I blast the door, sending it flying. I race to the cell in which the necklace pinged, not caring about doing justice to whoever imprisoned her. I find the cell to see her collapsed on the floor, my precious river. I smash through the cell flinging the door through the brick wall on the other side. I sit down and gently cradle her against me. I take off the inhibitor ring and push as much positive energy and love into her. Love? Have I gone soft? Have I truly fallen for the Changeling that I once called daughter? Yes, it seems I have, but it doesn't matter now. What matters now is that she is safe and she will live. I hear hoofsteps running towards me and put up a shield just in case. I turn to see Twilight and her friends, standing with Starswirl. Starlight is pushing at the shield, so I let her in. Soon all of the rest of them are too. I deny them all, as most of them sided with Starswirl when we first got back. Starlight was a villian just like both of us, so I am less guarded around her. "Starlight, I will transport you and her back to our house to our girls. Take care of her for me until I return."
"Of course Sombra. I won't let you down."
I send both of them home and turn to face the rest of the herd. "Starswirl, why do you not care about anyone but yourself and the Princesses? You target the creatures of my rein, but do nothing to try to resolve that hatred as we have."
"Sombra, this wasn't his fault, he was trying to help her." Twilight says, I'm assuming to try to calm me. Sorry, opposite effect.
"Help!!? Do you even care to hear her side of the story before taking sides!? Or better yet, do you even know what a starved Changeling looks like?"
"Yes I want to hear her side and no, I have no idea how to tell if a Changeling is starved. Starswirl says he was feeding her. He-"
"No! He fed her food, not emotion. Without positive emotion they starve. I hope you realize that she was starved of that emotion for eleven days Twilight Sparkle. You will be lucky if she isn't dead!"
"What? She has been gone eleven days?" She turns now addressing Starswirl, "You had her eleven days supposedly helping her? You could have very well killed her."
"Now Ms. Sparkle, it was never my intention to do that. I didn't know that sh-"
"YOU DIDN'T KNOW!! STARSWIRL! You are a liar. You knew that Changelings starve without emotion. You used to starve my troops in the dungeons under Canterlot, which is oddly what this area resembles closely."
"Okay, what if I did know that. Surely you can't expect me to keep alive the very creature Celestia, Luna, the Pillars, and I were sworn to destroy?"
"Darn tootin' you shouda. You, Mr. Dabearded, knew darn well that she was our friend."
"She was an absolute pleasure to have around. She always made our lives a little more interesting. Besides, now you have just admitted that you, well, kidnapped her." Rarity has a point there.
"Fine, yes. I finally figured out how to inhibit her magic, but I guess I missed a type. Pure dark magic. Only capable of being used by those who know darkness. So, time for the true test, Celestia."
As if on cue, Celestia and Luna appear in a flash of light. I pull all of the bearers to me, inside the shield. Twilight resists, so I let her stay out. Of course she won't choose the side against her mentor.
"Starswirl, your reasoning for summoning me and my sister better be good. I-" Celestia stops upon seeing me in a shield with all but one bearer.
"It is Celestia, I ask you here to pass judgement. These ponies come into my lab space unannounced and take one of my test subjects. One of who was a willing participant."
"He kidnapped Styx by force, and in turn has done injustice upon the very title that he holds." I say, keeping my voice steady.
"My dear Sombra, you must be joking, Starswirl? Kidnap somepony? Ha!"
I'm livid! I grab Celestia in my magic and teleport with her.
Styx's POV:
I slowly pry open my eyes to see Starlight floating a warm washcloth to my forehead. I look around for Sombra and don't see him. Starlight is giving off so much emotion that I feel quite rejuvenated, plus, I feel the rush from what Sombra poured into me while I was passed out. "Starlight, where is Sombra?"
"Back at the base where Starswirl held you captive last I saw."
"So why did a portal to the Dream Realm just open?"
"I'm guessing Sombra got angry."
"I need to go there now, but I need someone to take. Will you go with me?"
"Will I be safe?"
"Yes, nothing can harm you unless I will it."
"Then of course."
At that, I take us both there, through a portal, high in the sky. As we materialize on the other side I see a scene of horror going down. Sombra has brought Celestia up into the realm, and he did not do so by means of any normal unicorn magic. He did so by dark magic, as his eyes are neon green with violet flames streaming off. The nightmare he is making her live is where she is being turned to stone by the bearers of the Elements. So, Twilight and her friends. He is projecting his voice into the nightmare itself, "You know nothing of fear. You know only of power and coercion. You refuse to see the bad in somepony you always knew as good. The opposite is also true. You laugh when a mentor is accused of kidnapping, but you cry when you banish your sister for a crime less than that. Where do your morals lie!?"
"I don't know, maybe nowhere."
"Find them to undo the nightmare."
I decide to watch, not intervene, but Starlight had other plans. "Sombra, you saved Styx, Starswirl knows what he did is wrong, isn't that enough? Why do you have to torture Celestia? One crime is enough!"
I can't hold my tongue, "Starlight, you don't understand. This isn't torture, this is justice."
"If this is justice then what is torture?"
"Torture is putting somepony in a nightmare here in the Dream Realm and leaving. He will not leave until she has found the morals she needs to. Thankfully, no time passes in the real world while somepony is in here. This all happens in a second. This is why nightmares just appear, happen, and disappear in your head. Whereas dreams do see the passage time. The Dream Realm is a place of teaching."
"Really, this doesn't look like this is getting us anywhere. We know that Celestia will not find the morals."
"You are correct in that, Ms. Starlight, but this will give her time to ponder her decisions. Both past and present. I will release her soon enough, but not until she reflects. However, I think it is time for you to go."
Just like that Starlight is gone. I feel my bound connection change to Sombra. I feel the internal tug to go closer to him. Since he has one trapped in a nightmare, the realm expects him to put the other he is linked to in a nightmare or dream. He releases Celestia and we go plummeting back down to the ground, Starswirl's base. Celestia comes down and turns to Luna, "Luna, can you go into the Dream Realm in the middle of the day?"
"That takes a lot of power and energy, but I can if I need to."
"It is where I took her, showing and telling her what needs to change. And, now that Styx has joined us, we can hear the other side of the story."
"I was kidnapped by Starswirl, and I was starved of emotion. I only know of ten days, but another has passed since I passed out the night before. My magic was inhibited, and I was only able to activate my tracking necklace by a surge of pure dark magic. That was the last memory I had before passing out. So, Celestia, what have you to say?"
"Honestly, I don't know what to say, other than I have to side with Starswirl on this one. I can never know if the trust for you I have is enough. So, I'm sorry Styx, I am afraid I can't do anything for you."
I flare my horn, but Sombra puts a restraining hoof in front of me. I relax and let Celestia, Luna, and Starswirl leave. All of the bearers turn and look at me in disbelief. Of what I am not sure. "So, who do you believe, Twilight? Starswirl or me?"
"Honestly, I just heard two different stories from Starswirl, so I believe you. I can't believe Celestia believes him, after all, he never liked you from the start. Especially since you were associated with Sombra. Now I guess we can just go back home and relax."
"Agreed Twilight, let's go rest. I want to see Mystel and Orla again."
We teleport home at just the right time as the girls are coming home. Starlight was teleported back to Twilight's castle to meet up with them. I open the door for the girls and they come flying in. I hug them tight, not wanting to ever let go again, but knowing I will have to sooner or later.