Okay, if the title didn't catch your eye here is your last warning THIS POST WILL SPOIL THE ENTIRE STORY OF SONIC FRONTIERS.

ALL OF IT.

SPOILED.

YOU HAD YOUR CHANCE - SPOILERS TO FOLLOW

I finished Sonic Froniters last night (With the True Ending, despite not playing on Hard mode - maybe it unlocks if you have all stats MAX as well?) and I walked away thinking that Eggman was doing the right thing the whole time and Sonic is ultimately the cause of Sage's (near) death and the unleashing of The End to begin with.

The opening shows Eggman discovering the Ancients ruins and deploying his new AI Sage to investigate. Security measures are deployed that drag Eggman into the artifact and he finds himself in Cyber Space with Sage.
We don't know how long Eggman and Sage are in Cyber Space however there are 20 voice logs available from fishing before the 21st log mentions the arrival of Sonic. It is safe to assume that they have been here for sometime before Sonic, Amy, Tails and Knuckles are inexplicably drawn into Cyber Space.
Because Cyber Space is actually an ancient digital prison holding The End. The Ancients were forced to flee there alien home and retreated to Sonic's world where they valiantly fought a last ditch effort battle against a world ending force known as The End. Despite their incredible technology they are on borrowed time, Sonic's planet does not have the same resources and features as their home world and their technology does not adapt to it as well. Their numbers have dwindled following whatever conflict forced them to leave in the first place and they are fighting a losing battle. Piloting the Titans the very last of the Titans give their lives to trap The End within one of the Titans and lock it and themselves within Cyber Space.
Enter Sonic. With nothing to go on he gets a vision telling him to destroy the Titans to save his friends. He begins blindly gathering resources and attacking robotic constructs to complete this task with no understanding of what he is actually doing, even as doing so slowly corrupts his body and causes him to grow weaker and weaker.
Sage has sensed Sonic's presence and alerted Eggman to his arrival. Now, Eggman has been in Cyber Space for some time and I think it is safe to assume that the voice (later revealed to be The End itself) probably called out to Eggman too and told him to destroy the Titans to free himself. Eggman and Sage are far smarter than Sonic, however, and did their research to determine that destroying the Titans would result in the release of The End. Which brings me to my first major point:
Evidence #1 - Eggman and Sage, realizing that the obvious path out of Cyber Space will doom the real world to extinction at the hands of The End, choose to remain imprisoned and seek alternative routes back to the real world, despite Sage's calculations that such an alternative does not exist. Ultimately, Eggman would die in Cyber Space never to be seen again rather than release The End on the real world.
Sonic continues battling Titans even as Sage tells him the corruption he's absorbing will surely cause him to fail and that he doesn't know the impact of his actions. Sonic disregards this advice purely on gut intuition and a selfish desire to save his friends. Taking down more and more titans he finds himself at the final containment system for The End - a series of towers that must be deactivated in order to release the abomination.
Evidence #2 - Despite plenty of evidence he is working in a counter intuitive manner (his body being corrupted, Sage urging him to stop, the visions in his head becoming more and more frantic, artifacts from the Koko, and no logical reason to trust the voice in his head) Sonic chooses to shut down the towers without a second thought, beginning the process that will release The End from its prison.
With the towers disabled The End begins to awaken in the Titan it was trapped in so many many years ago. Sage and Eggman discover a completely frozen Sonic who has no been completely corrupted by his actions and rendered effectively dead. Tails, Amy and Knuckles are freed from their prisons as promised by the ominous voice, however they have been released simply to be destroyed by The End as it continues its rampage. Barring the miracle that occurs next, Sonic has doomed the universe to destruction. Thankfully, Tails, Amy, and Knuckles are able to.... I don't know what they do there is nothing in the game that explains what actually happens here. We see Tails, Amy and Knuckles form a prayer circle around Sonic and they disappear (sucked back into Cyber Space?) and in doing so Sonic is revived and able to fight again. This seems to be a soft sacrifice where if Sonic succeeds they can be freed again but should Sonic fail they will likely be trapped/dead wherever they just went.
Sage recognizes that Super Sonic is their only hope of defeating the Titan housing The End so she begs Eggman to form an alliance with the very idiot who created this whole mess: Sonic. Sonic, Sage, and Eggman split up to find the Chaos Emeralds one last time and when Sonic and Sage return with 6 Emeralds and no lead on the final Emerald Eggman returns to begrudgingly provide Sonic with the tools to succeed in his fight. Sonic once again fights and defeats the Titan as Super Sonic but this time it's not enough. The Titan isn't the real enemy and The End has bought enough time to return to its full form. The End leaves the Titan and floats off into space to begin raining death upon their world. Sonic is oblivious to the danger until Eggman and Sage point out that this isn't over yet. Sage takes over control of the Titan Sonic just defeated and joins Super Sonic as they dash into space. Eggman says a prayer for his digital daughter.
Once in space Sage uses the Titan to protect Super Sonic from a giant laser beam then hurls him like a bullet at the now Moon-like The End. Sonic bursts through the planetoid and out the other side causing a cascade of red energy to flow across the surface. Sage quickly determines that this is not The End dying, The End is preparing a final explosion that will take out Sonic and Eggman's entire planet. She hurls the Titan she's piloting into The End and detonates herself from within the core and saves the universe from obliteration at the cost of her own life.
As star fragments shower down a tearful Eggman looks up at the sky and mourns the loss of Sage. The daughter he created and loved was taken from him too soon.
So what does Sonic do? He touches back down safe and sound as Super Sonic and rejoins his friends Tails, Amy and Knuckles. They laugh and Sonic makes a joke "That was fun huh?" and they fly off into the sunset, none of them saying a single word to Eggman.
Evidence #3 - Despite not having a chance in hell of getting through any of this without Eggman and Sage, Sonic doesn't even recognize the death of Sage. He doesn't join in mourning her loss, he doesn't attempt to comfort Eggman, he doesn't thank her for her sacrifice. HE LAUGHS.|

Sonic is a fucking monster.
Thankfully, a post credit scene only obtainable via true-ending reveals that Eggman has been able to find/rebuild at least a portion of Sage he has found within the Titans wreckage as evidenced by the Ancient Hieroglyphs shown on screen before she speaks. However, it is also important to recognize that these same Hieroglyphs were shown when Koko released the stored memories of past battles to Amy, Knuckles, and Tails in their side stories. It is entirely possible that Eggman is not hearing Sage in this scene, but instead a memory projection of Sage stored within a Koko or similar Ancient technology as her will was as strong as that of the Ancients and she imprinted on their tech the same way they did. Just as the Ancients cannot be resurrected by extracting their memories from the Koko, Sage likely cannot be resurrected from these memory imprints, and the post-credit scene is more akin to Eggman watching old home videos of his late daughter.

Tell me I'm wrong, you can't.

You're wrong that the post credit scene is only available if you play on Hard or have max stats or whatever. It is just part of the normal ending. Others have claimed it's locked behind hard mode but I think they may have patched that out because, uhhh...the ending is a huge downer if Sage dies.

In terms of Sonic being a monster, you're wrong there too. What you're failing to realize is that Sonic has saved the world from being destroyed like a dozen times. It's literally what he does. This is NBD to him. He never had any doubt he would succeed, so he focused on saving his friends AND ending the threat forever.

Additionally of COURSE Sonic doesn't comfort Eggman. Do you know how many times Eggman has tried to kill Sonic and his friends? Over and over and over. Eggman only wanted the Ancients tech to kill Sonic. This is like saying Zelensky is a monster for not calling Putin to comfort him because his war is going badly.

As for Sonic not mourning Sage...I mean...she did try to kill him too. So there is that. And she was just a computer program. Sonic is focused on having a chili dog with his best buds and not worrying about the cyber daughter of Mobius-Hitler.

Look I'm not saying Eggman is a series wide good guy but he was guilty of being overly cautious at best here.

And while I get the gist of what you're going for let's not compare a mad scientist guilty of some fucked up animal testing and kidnapping a few magical girls to real world genociders.

@dareitus: Wow. This is a ludirous re-writing of Mobius history. Dr. Eggman is a monster. Have you forgotten the horrors he inflicted when he took over the planet? Look at this documentary:

And in the original Sonic games he did more than capture some animals. He grabbed all of Sonic's friends and imprisoned them in evil robots determined to kill him.

Then in Forces he oppressed the WHOLE PLANET and tortured Sonic for months. For months.

Not to mention the events of Sonic Unleashed where he DESTROYS THE PLANET.

He has awakened Dark Gaia. He has unleashed Iblis through the Iblis trigger. He enslaved Chaos and unleashed it against Sonic and the innocent people in Station Square.

He is the worst person in Mobius history and here you are saying "why didn't Sonic comfort him when he had a sad? What a monster!"

SONIC HAS TRAUMA! HE WAS TORTURED FOR MONTHS!

This post is nothing but savage victim blaming.

All's well that ends well, right? Sonic and his friends have always been amoral monsters, as shown by the ending of Sonic Adventure.

People can change. Eggman has matured and created better inventions (Sage), learned restraint, (Not unleashing The End even though it meant staying trapped), and learned to accept help even from old adversaries (teaming with Sonic).

Sonic has learned.... Nothing. He's brash, irresponsible, and clueless. He probably didn't even know Sage was an AI he just didn't care that someone died because he couldn't finish off The End (even though he was SoOOOoooOoooO confident he could). Sage gave her life to undo yet another one of his fuckups and he couldnt even be bothered with thanking her or telling her dad.

Eggman has been torturing animals and trying to kill Sonic all this time for a reason. He knows these magic/alien animals are a blight to human society.

I mean, let's be real. Mobius would be much better off without all those player made monstrosities from Forces running around.

Incredible, 10/10 thread, no notes.

@bigsocrates: just posting to say this was a fun reply and well done.