Return of the last survivor

Jack was like Merlin's best friend during the latter days of the Apocalypse, not only brothers in arms, but also sworn brothers. And seeing this kid's face, it did resemble Fireball-Jack's face, only without any scars of battle. It was a unharmed as a baby's bottom.

But Merlin decided to help out Jack for that one reason.

"My ability allows me to see things much further than one day as well. In fact, I have already seen a few years into the future."

"…" Jack was beyond disbelief by this point. The one in front of him could see the future. How could he not be nervous and scared. "S- Sir Merlin, What happens in the future?"

Merlin shook his head and said, " Do you know the butterfly effect?"

Jack thought for a bit and nodded slightly. By now, Jack had relaxed slightly, not that afraid for his life as before.

"It is when you go back in time and make a small change. That one small change can change the future completely. Even the act of killing a butterfly can have this effect, therefore the name."

"Yes. Now, what happens if I tell you information about the future, wouldn't it be equal to launching a nuclear bomb in the present reality and messing up everything?"

"…" Jack suddenly understood what he was asking. He was asking Merlin to destroy the future completely, for his simple request of knowing what would happen. It was a terrifying realisation of knowing something you shouldn't.

"But since I have already changed the future simply by looking into it and creating this force of mine, I will bend the rules slightly and tell you some of it. Things will only keep getting worse from here on. Far worse than you can ever imagine." Continued Merlin with a solemn expression.

Jack realised something at this point. Not only was Merlin terrifyingly strong, he was also carrying an equally terrifying burden. The burden of knowledge from the future.

"Alright. So here is what I will do. You will work under me for the time being. I will help you become stronger until you can fend for yourself. At that point, we can part ways."

"…huh? Wha-"

"Don't misunderstand. I'm not doing this to bring you over to my side. Let me tell you something. I do not see the future, nor can I decided what I see. But what I do see comes in fragments, and I do not see them. I experience them. As though I was there…" At this point, Merlin's thoughts trailed off as he stared into the distant sunrise before continuing.

"I am doing this to repay a debt from one of those memories. Let me say this once, and only once. Fireball-Jack, you must live your life exactly how you want to. Do not trust anyone, and don't become anyone's servant. Live your life to the fullest over the next few years. Now go! Leave!"

With this, Jack was pushed away by a huge amount of mana, which made Jack go pale. By the time he left the room, Merlin was already in tears when remembering his past experiences. His bitter struggle to survive. The number of friends and family that were lost during that time. The number of people who sacrificed themselves for Merlin, do that he could live on. Only to ultimately die in vain as the rest of humanity was whipped out.

Outside the room, Jack was in shock. Not only from the mana burst, but from the few clues he got from Merlin's words, and their implications.

At this point, Jack was already considering Merlin's words to be a taboo, never to be discussed with anyone. But what he understood from the conversation was nothing good. The debt Merlin was talking about was likely from his future memories, and was likely related to himself or some relative. Maybe even someone who resembled himself. But the fact that Merlin had said 'fireball Jack' meant that this debt was likely from himself. However, the most terrifying word Merlin said was 'next few years'. What did this mean. Something would happen after this period of time, and only Merlin knew what it was.

Jack was experiencing too many emotions right now, and decided to just follow Merlin for now, and put the rest at the back of his mind.