I do not own Ben 10 or any characters below.

This is a oneshot that was rattling around in my head for a few days now.

Professor Paradox had been traversing the timeline for at least 60 years in standard time now, but if you count how far he's traveled in time, its been 100's of thousands of years into the future and into the past and he's seen how things should be and not be. He'd setup a place to live and relax in the time stream so he could monitor it from time to time to ensure nothing out of the ordinary went wrong. It was just another day in the time stream when the Professor felt something was drastically wrong with the time stream and he needed to find out what happened.

He began working his way forward in time from a point he new nothing had been altered. As he gradually moved forward in time he saw things as they happened and could remember them fondly. He saw the birth of Kevin Levin, and then a year later the birth of the cousins Ben and Gwen Tennyson. 10 years later he saw Ben find the Omnitrix and the events that followed. Five years later he saw Ben and Gwen reunite with Kevin in their hunt for Max Tennyson and the fight with the DNAliens. The relationships seemed to be on track and how they should be so he jumped forward to Ben's 18th birthday and noticed something was definitely wrong. Ben was there with his parents, Max, Verdona, and the plumber kids, but there was no Kevin or Gwen. This was not right, so he started to slowly go backward from this point to see what had happened.

It took the Professor a few minutes but he found the point in time that changed everything. It was Kevin proposing to Gwen 6 months before Ben's 18th birthday. The professor new this was wrong Kevin was supposed to propose to Ben not Gwen, this was not good. The professor then jumped forward a year and saw that Ben was fighting on his own, he hadn't seen Kevin or Gwen since a month before his birthday and didn't attend their wedding. Their relationship seemed to have broken down after that and they were no longer friends anymore, although they seemed to have parted on good terms, Kevin and Gwen were living the ideal life with a house and white picket fence but no children, something that the Professor new the reason why. While the Professor was watching the different events unfold of Ben fighting aliens on his own now and Kevin and Gwen living a simple life he felt a major shift in the timeline from somewhere in the future. He began scanning ahead to find what had happened and he found it 10 years later. There in the middle of Bellawood stood a statue of Ben Tennyson with the Omnitrix and his most famous transformations in smaller form around him. The inscription read as follows:

Benjamin Kirby Tennyson
Wielder of the Omnitrix
Defender of Earth and all Sentient life
September 1995 – June 2023

The Professor couldn't believe what he was seeing, Ben was dead, what had happened, how did it happen. He immediately jumped back to June 2023 and began scanning each day to find out what happened and when he did he was sick to his stomach, he new why it had happened and who was responsible but to think that Ben was gone at only 28 years of age was sickening. Then something dawned on the Professor, if no Ben what happens in 2040 without Ben. The Professor immediately jumped forward to that date hoping and praying for the best but know it would be. When he arrived in 2040 his worst fears were confirmed Bellawood was gone completely destroyed, humanity had been enslaved by Vilgax who was marching across the galaxy in a war of domination. The Professor had to sit down and try to make sense of what happened. He knew where it all started to go wrong but he needed a moment to figure out what to do. He had to go back in time to find out why Kevin proposed to Gwen instead of Ben, those two should have been together for at least a year prior to that proposal to Gwen. He'd seen their relationship blossom and new that Kevin and Ben were meant to be together. After gathering his thoughts he stepped back into the time stream to venture back to March 2013. The professor found the date where Kevin proposed to Gwen but he needed to know why he wasn't with Kevin. He new the date that those two got together for the first time as the ripple through the time stream nearly knocked him off course, but that was how the time stream reacted at times.

Ben Tennyson was what you would call a nexus in time, when he moves or turns the time stream turns with him as does the rest of sentient life. Kevin Levin is his soul mate and what most people don't know is that Osmosian's can only truly love one person in their life and that is their soul mate, and when they find that person and mate with them they will love no other and will only be with that person for the rest of their lives. This little fact is not known outside of the Osmosian society, what also is not known is that an Osmosian or even half Osmosian will not impregnate someone else they are with if that person is not their soul "mate".

The Professor went back a year to when Ben and Kevin were supposed to get together and finally reveal their feelings for each other but what he saw was nothing of the sort. Somehow Gwen seemed to have realized she was not Kevin's love interest and she didn't like it, so she seem to have found a spell to fix her problem and make Kevin hers. This was unforeseen, but not unfixable he would need to scan back in time to when she discovered this and decided on this reckless course of action. He began scanning back to a point where he could intercept her before she did anything drastic and convince her of her egregious error.

Gwen was reading through her spell books trying to find a spell she could use to make things go her way. She wanted Kevin, she felt she was meant to be with him plain and simple, she'd been attracted to him since that day at the train yard but he'd never gone any further than hugs or simple kisses on the cheek and only a couple of full on kisses. Gwen had noticed that Kevin and Ben had been getting closer and closer and realized that their feelings were for more than just friendship and she didn't like this, Kevin was her's not Ben's, he could have anybody else but not Kevin!

"I won't let him take Kevin from me, I'll find a way to keep him!" Gwen stated to herself.

"Gwendolyn!" Gwen jumped in shock, she turned around mana at the ready but relaxed when she saw it was Professor Paradox.

"Professor, what brings you here, you usually only appear to Ben?"

"Your meddling brings me here Gwendolyn!" He stares at her with a hard stare.

"What do you mean my meddling?"

"The spell you are looking for to ensure Kevin stays with you and doesn't get together with Ben next month."

"Wha…how did you know?"

"I travel the timline Gwendolyn, I felt the ripples of change that affected the timeline what you cast the spell and I've come to stop you."

"You can't, Kevin is mine, not Ben's, why can't I have what I want for once in my life! Why does it always have to be Ben!?"

"Gwendolyn, you don't understand the severity of your actions. Give me your hand and I'll show you and explain why they belong together, I'm hoping showing you the results of your actions will resonate with you but if not I have other ways of preventing what I saw."

Gwen stared at the professor she was furious, Kevin was hers, but she knew she couldn't harm the professor he was in essence a being out of time and untouchable to her. She reached out and took his hand.

"Where are we going?"

"I'm going to show you what your meddling did to the timeline."

"First stop is Ben's 18th birthday. Please know that they can't see us we are out of time to them."

"Ok."

The timeline stopped and there in front of Gwen was Ben's 18th birthday everyone was there, no wait, not everyone, she nor Kevin were there.

"Wait were are Kevin and I?"

"Unfortunately neither of you attended Ben's birthday, after you cast your spell and Kevin proposed to you the relationship between you 3 started to break down."

"Next stop is a year from now at your wedding to Kevin. Do you notice something missing?"

Gwen looked around, eyeing the crowd and everyone there, she saw her friends from school, her mom and dad, brother, aunt and uncle and grandpa Max, but no Ben or Plumber kids.

"Where's Ben and the Plumber Kids."

"At this point you and Kevin are no longer Plumbers and do not work or fight with Ben as a matter of fact you 3 haven't spoken in over a year."

"What how could we not be plumbers anymore?"

"Well Gwendolyn, there are consequences for every action you take and without Ben to control Kevin he reverted to his old ways of stealing and stole some high tech plumber gear from the base and was hence forth divested of all plumber access and since you defended him you were as well. Max attended the wedding as he was family but Ben wouldn't and just so you know, you never spoke to or saw Ben again until 2023 but we'll get to that in time."

"Ok so Ben, doesn't speak to Kevin and I but everyone seems happy."

"Gwendolyn, I am now going to skim through the timeline at a pace where you can see it and how things progress. We are currently in the year 2014 so pay attention to what you see and watch."

The time stream started to move but Gwen could see and understand what she saw. She saw Ben fighting and defending the earth against attack after attack over the next 9 years, she also saw the plumbers and Max helping him. Then she saw her and Kevin living a simple but happy life in a house with a white picket fence. She smiled.

"I bet we have cute kids."

"You don't have any kids with Kevin, Gwendolyn, and you never will in this timeline."

"Wha…! Why?!"

"Because as an Osmosian or even half Osmosian they can only impregnate the one they are destined to love as a soul "mate" and unfortunately for Kevin that is not you. Only the person he is destined to be with in mind, body, spirit will he then have offspring."

"What….your lying! I've never heard of that."

"That's because the Osmosian society keeps it a secret except to them, I don't think Kevin even knows about that part."

Gwen just stared at the Professor, she got Kevin, the house, white picket fence but no children because she was not his soul "mate".

"Gwendolyn, the next events you are going to see are disturbing but you must see them." The professor started the timeline rolling again.

Gwen saw Ben fighting eventually it was just him, he decided to not have a team and the plumber kids went off on their own team missions separate from Ben, he did well fighting by himself but he looked sad and forlorn. He had moved out of his parents house at 19 and into a small apartment a few miles away but close enough to the base if the needed him, but he was alone, he had no one to spend his time with, when he wasn't fighting he was either at home sleeping or working out but that's it, no TV, no video games, no friends. She saw Max would stop by now and then and visit but Ben seemed different.

Then she saw it the statue of Ben surrounded by his most famous transformations then she read the inscription and saw the date, her eyes went wide at realization. Then the timeline went backward to June 2023. The Professor showed Gwen what happened to Ben.

Ben was sitting in his living room, he was holding several envelopes, one addressed to his parents, one addressed to Grandpa Max, and one addressed to Kevin. There was a gentlemen standing there waiting for instructions. Ben finally spoke.

"These letters are to be delivered exactly one year from today, no sooner, no later do you understand."

"Yes Mr. Tennyson. Is that all."

"Yes, please stop by later tonight to take care of what I asked you to do."

"Yes, sir, have a good evening." The gentlemen left not knowing that when he returned would be one of the most painful events he'd have to deal with since working for Ben.

Ben was whispering now…"I'm sorry mom, dad, Grandpa Max, I tried to move on, I tried to see other people and find someone to fill that hole in my heart and soul but there is no one else, its been 9 years and the pain is still there in fact its worse and I can't do it anymore. I hope you can forgive me."

Gwen was screaming at the top of her lungs tears streaming down her eyes. Then she saw, Ben put a level 5 lance to is temple and pulled the trigger killing himself.

Gwen stared at the now dead body of her cousin, is this really her fault. She watched the time tick by and saw the gentlemen from earlier return and with stoic resolve called the authorities and Ben's parents and Grandpa, he let Grandpa Max call Gwen and Kevin. Ben's parents and Grandpa were a mess and crying when Gwen and Kevin arrived not knowing what was going on, when they walked in and saw Ben's lifeless body lying on the couch Kevin collapsed screaming in pain at the top of his lungs.

Gwen saw Kevin go mad with rage and transform into his old mutilated self from when he was little and he charged her, but she threw up a mana shield to protect herself, luckily there were plumbers there to subdue him and take him to the plumber base.

"Why did Kevin attack me?"

"Because Gwendolyn, when Kevin saw Ben's dead body, the spell you placed on him all those years ago broke because his Osmosian side saw that his one true soul "mate" and love of his life was dead and he would never know love again and that part of him truly had died"

Ben's funeral was held a week later, no one was told how he died, a cover story was built around it to keep his untimely true demise a secret. The whole town of Bellawood and people from all over the world came out to pay their respects to the hero of Earth even aliens were there including Azmuth, who was actually crying as well.

The timeline began to move again, it was now June of 2024 and the mysterious gentlemen delivered the letters as instructed. Kevin's was given to Gwen at their house as Kevin was still in containment at the plumber base as he had gone insane with rage and grief at the loss of Ben and he never returned home, Gwen would visit him but he would never look at her after that day.

Ben's letter to his parents:

Dear Mom and Dad,

I know this past year has been tough on you, and I wish I could have been stronger to get through my pain but I wasn't seeing him with her and knowing they were together was to painful for me to carry anymore. I've loved Kevin since the day I met him and I thought he loved me but I guess something changed, I don't know what that is but I can't go on like this anymore. I love you both dearly but my life has no meaning anymore, I'll I do is fight aliens but that's a job not a meaningful life. I hope in time you can forgive me.

Love Your Son,

Ben

Ben's letter to Grandpa Max:

Grandpa Max,

How can I begin to say how much I love you? I know you probably won't understand some things but I couldn't go on like this anymore. At first when I was 10 I loved wearing the Omnitrix, then I reunited with Kevin and Gwen and we were a team, then somehow things changed and my life was less fun and had no meaning. You were always there for me even the day before I died, I know you knew something was up but you couldn't figure out what. I'm sorry for all of this. I hope in time that you can forgive me. Please return the Omnitrix to Azmuth, it belongs to him, you know where its kept and only you can now open it.

Love Your Grandson,

Ben

Ben's letter to Kevin: (who never got to read it, but Gwen did)

Kevin,

I can only tell you how I feel. I love you with all my heart. I know deep down that you were my soul mate, and I know you now it too. I thought we were getting close back in 2012 but something changed, I'm not sure what, you then got together with Gwen, proposed to her and married her. After the proposal we never spoke or hung out again and I miss that. My life without you has no meaning, but I couldn't stand there and watch you kissing Gwen when I now deep down we were supposed to be together. I don't know how but I do. I love you, I always will even in death.

Love Your Soul Mate,

Benji

Gwen was standing next to the Professor in tears, did she really cause all of this because of her need to have Kevin.

"Gwendolyn, I still have more to show you, you need to see it all."

The time stream moved again and it was now 2025 and they were back at the statue of Ben but this time there was a statue of Kevin and the inscription read

Kevin Ethan Levin
Friend, Partner...
Always and Forever
June 1994 – August 2025

Gwen stared at the statue, realizing that Kevin was dead not a year later after Ben.

"What happened Professor?"

"When Ben died, the spell you placed on Kevin broke because is soul mate was dead and it was no longer needed. Once the spell broke Kevin realized what had happened for all those years and he went insane with rage and anger and sadness. He killed himself just over a year after Ben did realizing he would never feel love again.

Gwen stood there in dead silence she couldn't believe this, one simple spell caused all this, it couldn't be.

"I see your still doubtful of what I am showing you. I have one more thing to show you in this timeline before I show you the correct timeline."

The professor jumped to the year 2040 and what Gwen saw shocked her, they were standing there but there was no Bellawood and the sky was all grey and no sun.

"What happened here Professor."

"Vilgax happened Gwendolyn, without Ben and Kevin to stop him, he conquered earth and enslaved mankind and has continued to march across the galaxy conquering world after world, he now even has control of the Omnitrix after capturing Azmuth."

Gwen was staring at what was left of Bellawood infront of her, even the statues of her cousin and Kevin were gone and in their place was a statue of Vilgax claiming to be the liberator of Earth from its human opressors.

"Now Gwendolyn, I need to show you another timeline." With that Professor Paradox snapped his fingers and a new timeline flowed past Gwen. In it she saw Kevin and Ben get together, get married have 5 kids, defend the earth, defeat Vilgax for the final time, and other enemies. She also saw herself married to Pierce from the plumbers and they had 3 kids, she seemed happy and they all spent time together, life was good and Ben and Kevin were alive and well and the earth was flourishing.

Once the timeline was finished Gwen found herself back in her room but now Professor Paradox, but she did here a warning.

"I will be watching Gwendolyn, You have been given a glimpse into what will happen if you continue down this path. I am a protector of the timeline and will do all I can to protect the future of earth and those that defend it."

Gwen sat there in her bedroom for the next week, not coming out to see anybody or anything, she wouldn't even come out for her parents or brother. Her father finally had to call in Verdona.

Verdona appeared in Gwen's room. "Gwendolyn, what is up with you, you father says you haven't left this room in a week, and from the smell of it, he's telling the truth!"

Gwen looked up at her Grandma with sad eyes.

"Gwendolyn what's wrong?"

"I had a visit last week by Professor Paradox, he took me on a time trip because of something I was going to do."

"What were you going to do Gwendolyn?"

She couldn't look at Verdona when she said it. "I was going to cast a spell on Kevin to make it want me and not Ben, I can see them getting closer together."

"Gwendolyn! That is a violation of everything we stand for, why would you even think of doing something like that?"

"I love Kevin and I want him for myself at least that's what my mind is telling my heart."

"Gwendolyn, you can't have Kevin, he's not meant to be with you, he's meant to be with Ben, I've known that since the first time I met you three at the lake. Ben and Kevin are what we Anodite's call a time nexus, where they go the timeline follows, and so does all sentient life, besides Kevin and Ben are meant to be together. Did the professor show you both timelines what would happen if you cast the spell and what happens if you don't?"

Gwen shook her head yes.

"And?"

"I did not like what I saw in the first timeline, Ben killed himself, and Kevin did so a year later, and then in 2040 earth was conquered by Vilgax, without Ben and Kevin we were helpless."

"Gwendolyn, I know you like Kevin, but love really, you just like him for eye candy, don't you, its nothing to be ashamed of, your human but you have to understand that you have someone out there for you as well and he will come around in time. You just have to be patient but you also have to let Kevin and Ben come together or bad things will happen."

Gwen nodded in understanding, she still didn't like it but really was she willing to risk the wrath of Professor Paradox and her full Anodite Grandmother.

In the end Kevin and Ben got together, and on Ben's 18th birthday Kevin proposed to Ben and Pierce kissed Gwen for the first time. Six months later Kevin and Ben were married and not to long after that Ben was pregnant with their first child whom they named Devlin, the second was named Kenny, the third was named Max, then Kevin Jr. and then Ben Jr.

The statues of Ben and Kevin were built but were in honor of them and their ongoing fight to protect earth. When the time came they defeated Vilgax when he came to earth and that was the last they ever saw of him.

Gwendolyn and Pierce took it slow but they finally got married a few years after Kevin and Ben and ended up having 3 kids named Maxine, Samuel, and Sandra.

The Professor sat back in his chair in his comfortable home within the timeline and smiled to himself. All is right with the timeline, and now I can rest after that harrowing adventure.