HDXD: Omni Harem System

『Incoming System Alert – Message Transmission Request Detected』

Past Adam blinked.

"Huh?"

The voice of his System echoed in his mind with a sudden and unexpected message.

『You have received a secure transmission from... yourself』

"…Come again?"

Past Adam asked, even more confused than he was now.

『The sender matches 100% to your spiritual and cognitive signature. Shall I allow it to play, Master?』

Adam narrowed his eyes.

"You're saying future me sent a message back in time? No rather he most likely use Memory Point, and use his system to send a message to mines."

"Still I never knew you could send message back and forth with different version of yourself."

Past Adam said with a surprise.

And his System, began to reply how it works.

『Future Adam is a version of you from the same linear timeline, but he is further ahead in time, he is also the one leading ahead all Adam as the leading one driving the future forward at its wheel. Beyond that point, the future is undetermined. Essentially, he is you, just in the future. All versions of Adam from the same timeline can send voice messages through the System, as long as they are within the same time period. And to answer your other question, you just never asked before』

"I see, either of way, play the message."

A faint crackle then began to echo in Adam's head.

As he began to hear his own voice, distorted slightly from the bone mask, but it came through.

"Past me, I need you to listen carefully. I don't have time to explain everything in great detail. But you'll understand soon enough."

"Alustus cannot be killed by brute force. Every attack we land only fuels him. His body is like a pressure chamber. His internal barrier converts kinetic energy into stored compression, then reflects it back stronger when he physically attacks back."

"Keep in mind he also has no organs. Just a heart. A brain, and a skeleton. Everything else is flowing blood. Hitting him directly is a mistake unless it's from surprise or at a weak point."

"He is vulnerable only if caught off guard. The moment his focus slips, even for a second, you strike. That is your window to finish the bastard off once and for all."

"You'll know when it is time, for now I will destroy the portal from where I am, just kill the remainder of the Sidhe. I will also leave instructions on the blade you will need to make to conquer his barrier, also trust the woman, and don't be suprise to what you see."

"And when the second blade appears… follow its lead."

"…Good hunting, me."

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『Master Alustus is Dead』

The system explained to Future Adam, confirming their joint worked to kill this bastard.

On the other hand Future Adam stood before the headless corpse of the Sidhe King. As he looked down at the body, his expression unreadable beneath his bone mask.

But seeing this Berreta drop on her knees as the corpse of her husband layed bare before as she began to cry silently to herself.

Ignoring the two Adam's completely.

On the other hand as Future Adam look at the corpse he said out loudly.

"What a pain."

He muttered coldly.

"I'll second that."

Came a voice from behind.

Future Adam turned slightly as Past Adam floated closer beside him, his claws and blade still wet with blood from both killing Sidhe, and beheading Alustus.

They then both stared at the corpse for a moment, then simultaneously looked up.

As they noticed something began to arise from it.

There, hovering in the air, was Alustus's soul, slowly drifting free of his ruined body.

Clearly preparing to go somewhere, but before it did, whatever it was going.

Future Adam spoke calmly to Past Adam.

"Go ahead. You know what to do."

Without hesitation, Past Adam activated his Box of Worth, and seized the soul as the Black Box ate everything. A flash of light exploded outward as the box devoured Alustus's entire existence...past, present, and future alike

In an instant, both Adams were flooded with memories, as all of Alustus's secrets, plans, powers, feat, regrets, even the alternate future he might've had if fate hadn't introduced him to Adam.

Flood through them both as they took everything from Alustus's.

Leaving nothing behind at all.

They saw it clearly, his worthless no good hikomori past pre- reincarnated self, his pre-present self, and the stronger, evolved version of Alustus, two years down the line. Cold, brutal, and more refined than ever.

Soon as the memories fade, both Adams commented on what they saw.

"…What a fucking loser."

Past Adam said bluntly.

While future Adam just smirked.

"Died like a chump to think his own son would have conspired against him with a stronger foe, and killed him two years from now. Still, I must Admit, he looks way cool in his future, though. Peak A-Rank still, just way stronger. Too bad he ran into us."

Past Adam rolled his neck, as he nodded in agreement, and then said.

"So, what now?"

Hearing this Future Adam crossed his arms, and replied.

"Well, thanks to this, we gained a ton of new abilities, and stolen fate across past, present, and future. Even picked up a new system… but I'll sort that out when I return."

Past Adam gave him a look. He could see it but knowing himself he could guess what Past Adam wanted to say, and just as he suspect Past Adam asked the question.

"Speaking of… how the hell did you get his wife to betray him?"

Future Adam just shrugged and said going with the flow of the conversation.

"Ah, her? Don't worry about it. Either way, I should head back to the future now."

"Wait...hold on!...

He verbally said, finally asking the true question Future Adam would have asked if in his situation.

"If you leave, what happens to me? I didn't do the stuff you did to become you."

Future Adam looked at him with a grin, behind his own mask and replied.

"Technically, I am just you… from later in the same timeline. So don't stress it. We're the same thread, the only difference is that I am just a few pages ahead in a more confusing way."

But before he could speak, another voiced came in with a more proper explanation.

Just then, both Systems chimed in, one after the other.

As Future Adam's System spoke first and both Adam heard it explanation.

『This past worldline will not change. It is the cause. However, the future worldline that Future Adam came from will be rewritten. The death of Alustus in the past ensures that he dies in the future as well. Cause and effect are now aligned』

Said Future Adam's System.

And Past Adam's System finished the explanation.

『When Future Adam returns, his body will physically be deleted alongside the future he came from, but his existence, memories, power, and knowledge will remain. They will all transfer without fail to Past Adam when he reaches that same moment in time where he jump from to reach the past. Future Adam body will no longer exist as a separate self of that non-existent future since it will no longer exist, rather he will exist as the effect of what must be in the rewritten future he cause to reach the intended result』

Hearing this Future Adam exhaled, his eyes closed, as he said.

"…So that is what happens when you travel into your own linear past to correct a problem to change the future."

『Correct. From your perspective you will remember everything as is alongside what past Adam experience in the gap where you jump from Point A to B, but in the new future only the intended change remains. The rest continues naturally. The more you alter here, the more the future will shift to reflect those changes as for the law of the Great Spirit of Cause and Effect dictates』

Right after, Future Adam turned to his younger self.

Satisfied with the answer, and then said to his past self.

"Alright. Do me a favor, will you?"

Past Adam raised a brow, but answer back.

"Sure. What is it?"

With those words Future Adam looked down at Berreta and began to say as Past Adam look at her as well.

"See that girl?"

He pointed at Berreta.

"Her True Name is Empussa. Ask the System what that really means, And make her explain what'll happen now that Alustus is dead. I figure since he overthrew the last king… and we just overthrew him…

He grinned.

"That makes us the new King of the Sidhe race."

Past Adam gave him a blank look, but soon smile and jokingly said at the thought of being king.

"Score more titles."

Future Adam chuckled.

"Yeah, yeah. But don't forget, Alustus didn't know much about the Demon World. She does. So milk her for information."

Past Adam just nodded.

"I'll figure it out. Now then I think it is about time you go before Minerva sniffs us out. I would not be surprised if she already suspects time travel BS from us since we already told her about Memory Point, and I don't feel like sharing her hugs and tits when she comes to congratulate us... I don't care if you are me, my time period, my Minerva so fuck off."

"Heh. You selfish bastard... But I couldn't agree more, if some alternate version of me hug my Minerva I would probably kill them even if they help me."

Future Adam smirked under his mask when he say these words, then end his last words with.

"Well, either way, I'll give Minerva a hug in the future and and of course boldly cop a feel for my efforts, so, in that spirit… fuck you too."

Past Adam rolled his eyes.

"Get outta here already."

With a final flash of green light, Future Adam vanished, returning to a future forever changed by the decisions made here.

FLASHHH!