Arendelle's Dark Winter: Elsa x dark powers male reader

Grief

You stood there, tears streaming down your face, your teeth clenched as Jack held Hans against the wall.
"Man. You really are a brat.", Jack said to Hans. "Believe me. If I were you, I'd start to choose my words veeery carefully now."
Hans started to look scared.
"Y/N?", Elsa repeated. "Is this true?"
You couldn't look at her. All you could do is watch Hans's every movement. And see Sarah's eyes losing their light over and over in your mind.
"I got tricked. I did not unleash that darkness. Neither did I kill anyone on that day.", you start.
"All I did, was grieve. Grieve for the one person who didn't abandon me. Me! She never saw me as a monster or a freak, like so many did! She died in MY ARMS!", you yell. Your blood is starting to boil.
"But I didn't lift a finger against the normal people. As much as I wanted to find a scapegoat. Or someone to blame! I wouldn't.", you start breathing. Remembering that day.
"But that's not what you're here for, is it, Hans?"
Jack let him go as he dropped to his feet.
"Why are your goons carrying weapons? If you're here on a peaceful mission to take the queen back?"
One of the goons aims at you.
Jack darts over and kicks it out of his hands.
"Ah. Ah. Ah. What do you think you're doing?", a toothy grin appearing in Jack's silhouette.
The other one was ready to fire, but Hans grabbed the crossbow and aimed it away, into the chandelier up above. It came tumbling down as you saw Elsa running. As it crashed on front of you, Jack grabbed you and slammed you into a nearby wall.

Hamelen, a few years ago

You were carrying Sarah's corpse all the way throughout the alleys. You had been walking like this for a few hours until the night almost made way for dawn.
Then, you found him. He wore his hooded robe as he appeared, seemingly out of nowhere.
"Well, well. It would seem the heist didn't go without a hitch."
You almost fall onto your knees in front of him.
"Bring her back...", you say, almost out of breath.
"No can do, dearie. There are rules to this, you know."
"Please...you can have my wish. I just want her back..."
You felt like a bumbling child. Asking for his prized toy back to a bully.
"Listen. Even if I wanted to, magic is limited. I can't bring back the dead, it's one of the rules."
He bows down, takes the potion and stands upright.
"You have a wish to make. What do you wish for?"
"For Sarah to come back...", you sobbed.
"It's not possible.", he laughed. You could hear his high pitched laughter.
"I can't understand why you would keep asking, if you already know the answer. You can ask anything. Riches. Fame."
You look down at Sarah's still face. You look up to him.
"I will keep my wish. Until I know what I want to wish for."
"Nothing? No revenge? No killing? No power? Absolutely nothing? Do I need to remind you of the fact that these people have continuously reject you and her? Or the fact that there is one amongst them, guilty of taking her life?"
You felt your anger coursing through your veins again. You wish you could be mad. But all you can feel is grief. And you can hear her words.
'Prove it, that you were really planning on building a future with me.'
"No revenge.", you said softly.
"It was just...an accident."
"You would forgive someone that easily?", he snaps at you.
"Don't mistake my actions for forgiveness."
"Hmph. Very well, keep your wish. If you're ready to wish it, just call me."
"How?"
He takes down his hood, revealing a man with scaled skin. His eyes look more animallike than anything else. His long brown hair was spread everywhere, unkempt, as he makes a bow.
"Rumplestiltskin. Say my name three times and I'll come grant your wish."
He giggled with that high pitched laughter of his.
"Anyway, I must thank you. You have given me what I needed."
He reveals a dagger, warped steel, wearing his name. He coats it with the gassy substance of the potion.
"Good night.", he simply says and laughs as he points the blade up and covers Hamelen in a dark orb of energy.

Arendelle, present day

You slowly wake up. You see the destroyed ice chandelier in front of you. The palace looks as if it has fallen to ruin. You get up, feeling your body ache.
You look around but notice no one's around.
"Elsa.", you think to yourself.
You start walking outside, your legs hurting like hell. Jack support you, putting your arm over his shoulders.
"Thanks, Jack."
"Find her. I know why you came back. She's a lot like Sarah, isn't she?"
You just remained silent as you struggled outside. The cold air started biting on your skin. You needed to get back to Arendelle.

You walk, for what seems a few hours. A reindeer just passes by with a man riding it.
"Who are you?", he asks.
"Wait. You were with Elsa in the ice palace. Where are you going? We need to get Elsa!"
"Hans took her.", you explain. "And I'm making sure that brat doesn't harm her."
"Well, get up!"
Within seconds the man has turned the reindeer around and pulled you on it behind him.
You hold on as you both ride towards Arendelle.
"Anna and Elsa are both in danger. We need to find them as soon as possible. Keep a lookout for anything-", he stops talking as you both see what looks like a snowstorm very localized in the middle of the frozen sea.
"...suspicious.", he finishes his sentence. He leads the reindeer further down the mountain.
It takes you about 10 minutes. This reindeer is extremely fast! But you hang on, to the best of your abilities.
As you arrive at the ice, you and the guy step off and run up the ice. You can see Anna, visibly cold. As she turns and tries to walk away.
"She needs to come to us! Please!", the man yells behind you.
Without a thought, you send out jack to hold her there.
As you run forward you can see Elsa.
And that brat of a prince behind her, about to swing his sword towards her.
"Elsa! Look out!", you yell!
You watch the blade get closer as she turns around.
It's almost like everything is happening in slow motion. Just like it was with Sarah.
Within an instant, Jack comes back and teleports you in between them as you grab the sword with a now blackened hand.
"Hello. Brat.", you say with a foul grin as your eyes, now pitch black, look up at him.