A/N: I decided to do some changes to my favor. So much changes. And yeah, Sennin is my OC. The meaning of Sennin is immortal, if I recall. It's a Japanese word, I think.

Disclaimer: I don't own Rise of the Guardians and Frozen. Just the OC and plot.

Sennin's POV

"Hey Sennin! Let's go on an adventure!" Jack Frost shouted while running towards me.

"What is it now, Jack?" My red eyes staring at him, one eyebrow raising.

"Just like what I said, let's go on an adventure. Let's go somewhere." Jack said grinning.

"Last time we went somewhere, we got lost. So, my answer will be no." I said, then started to go away. I obviously don't want to be lost again.

"Oh come on. It will be fun." Jack traps me with his stick that looks like a cane.

I sigh, "You know that I have a different point of view when it comes to the word 'fun'. And besides, where would we even go without getting lost?" I said with a look that says, "I know you don't know where that place would be."

"Hmm... " Jack tilted his head, deep in thought. Taking this chance, I started to walk away when suddenly, "I know! Let's go to Arendelle." Startled by his loud voice, I trip causing me to fall into a pile of snow.

Helping me up after laughing so hard. I asked him.

"Arendelle? That placed that you visited for like a few weeks?"

"Yep! Bulls-eye!" Jack said grinning widely.

"What are we even gonna do there? Hmm... Oh! Don't tell me you'll gonna visit the girl that you gave some of your powers with." I stated feigning surprise.

"Geez. Is it bad to visit someone I know?" Jack huffed crossing his arms.

Smirking, "But I wanna ask you. Does that person knows you?" Watching him lost for words, I chuckled.

"Okay, okay. Fine. I'll go with you. Better?" I said to him. He just nodded.

"But first, let's go tell North, ok?"

"Fine, whatever you say Sennin." Ignoring him, I started to walk towards the North Pole.

When he catched up to me, the two of us started to talk about random things, with a snowball hitting it and just avoiding it added.

When North finally gave up and let the two of us go to Arendelle, me and Jack high fived and started to go prepare things that we needed.

"Wait a minute, you two." North managed to grab both of us before continuing what he will say.

"I did agree to let you two go there but I didn't get the chance to tell you my condition." Jack groaned when he heard the word 'condition'.

"So what's the condition?" You asked North.

"First, the two of you will go there tomorrow. Second, as much as possible as you can Sennin, please refrain from telling anyone your true identity, you know that it can be dangerous for you. And lastly, don't get lost again you two. Do we have a deal?" North asked the two of us and I nodded. And Jack, well, "Why do we have to go tomorrow? Why can't me and Sennin just go there already?" I shook my head, elbowed his ribs and glared at him earning me a gulp.

"Want me to melt your statue that you're so proud of building?" I said, glaring at Jack.

"No, no and no Sennin. Geez, just because you can control fire doesn't mean you can use it against me." Jack returned my glare, thus starting a staring contest between the two of us. North coughed, interrupting the staring contest.

"Okay, okay. Fine! I agree. Glad?" Jack said irritation in his voice.

"You betcha, Frost!" I grinned at him.

Normal POV

And because Jack and Sennin still have time before they travel to Arendelle. They got pretty bored suddenly.

"Hey Sennin." Jack boringly said to Sennin. Asking him what it is, he suggested, since the two of them didn't have anything to do, that they should have a snowball fight. Thinking that it will be better than just lazing around, Sennin agreed to play.

"Hey! No fair. Don't use your fire power." Jack shouted while throwing a snowball at Sennin and before it hit her, she melted it.

Sennin chuckled, "You didn't said that I can't use fire." With a tone of matter-of-fact.

The snowball fight continue for a few more minutes with Jack irritated with Sennin using fire, and eventually she surrendered saying she's tired. Jack also agreed and said that the two of them should already go and take a rest for tomorrow.

Both of them excited for tomorrow.

A/N: I decided that I'll just recreate this story with my own. And Sennin here is a mage, an elemental mage to be exact. And for years of training and researching how to be an immortal, she became an immortal elemental mage. I'm just writing where my imagination will take me and I hope this would be good.

Maybe if I feel like it, I'll draw what Sennin looks like. Oh, and her forte is using fire and water. But she can use other elements.