Harbinger is a unique case within the Shatterverse, being considered an anomaly, a one off creature, he doesn't exist in any other Shatterverse nor the 'original' universe. It is theorised later by Sonic that maybe Bloodstone Harbinger is made up off the leftover DNA and evidence from Shadow, considering that he was not part of the explosion. Unlike it's friends, he would be incredibly unstable if he left Bloodstone Spire, if that is even possible, conisdering that he is unique to the world.

What went Wrong

Bloodstone Spire was not always the firey wasteland that it now is, the only land now being the so called Bloodstone Spires that rise out of the lava lakes. None of the inhabitants like to talk about it, all of them having taken on new names, most involving their role or something to do with the Bloodstone that sustains them within their names.
The world was always covered in lava, people stuck to hire land cause it felt more stable, but never previously to this extent, not when they were growing up. It was this universes Dr Eggman who caused the world to be how it is now, and within this he lost his own life; a suitable fate if you ask the Mobians. Their numbers are minimal, things happened fast, not all of them could get high enough, not all of them willing to remain in this tiny world.

Their world Now

They've had to adapt, find new ways to supply their food and cope even further with how hot their world now is. Harbinger had to change everything about himself, he had to become stricter, more serious and put their survival above everything else. Their original leader was their Tails, but he could not cope, could seperate previous friendships from then to how things need to happen now, so Harbinger stepped up.
This is when he 'earned' his new name, while not the official leader, he announces the approach of their leader. He orchestrates everything and a few believe due to his unique looks and the Bloodstone markings up his arms, that he speaks for the planet itself. After they meet Sonic and discover Harbinger is unique to this world, they further believe this idea, he does not like that they see him as some form of messanger of the world, because he knows he isn't. But in this world you have to accept the place that everyone has given you, even if you don't want it.

• Harbinger's rudeness is a type of self-defence he can't put his own feelings above the survival of everyone
• He has wiped out any recollection of who he was before the fires, that Mobian doesn't matter anymore not in this world
• He really loves people petting his quills, they're soft and fluffy, but publically he would scold you for doing this though, he has an image to keep up
• Sonic theorises that Bloodstone Harbinger is possibly a combination of Shadow & Tails, he's not sure what else whoever, or why this unique character exists. It's not like the council of Eggmen.
• The two black 'tails' come out from around his shoulderblades on his back, where the other black elements are. They have a level of prehensile ability to them.
• Uses he / they / it / just goes by 'The Harbinger'
• Craves to see what these other worlds look like, to know how the others live. He's heard of this all water world and is curious, water is something they savor and yet there is a world flooded
• See's Fire Pilot as a little brother, he's very protective of the titled 'leader'.