Madara had lived with his sentinel abilities since he was almost too young to remember, he knows he came online on his first battlefield and his father's pride kept him warm though the agony of learning how to use the Sharingan with his senses, kept him warm though the exhausting training to use his senses without zoning, kept him warm while he learned how to block out the input from guides he might meet on the battlefield- from any guide but one he wanted and chose- there weren't many (they were fewer than sentinels) by they could be wildly dangerous to him as long as he remained unbonded and he had to learn the clan techniques to protect him mind and keep them from controlling him. Anyway he was Uchiha and he didn’t need a guide, his clan could function without them- unlike almost any other bloodline- after all the sharingan and its abilities were uniquely gifted at protecting sentinels and keeping them from zoning, how could it not be when ticking the senses what such a large part of what the Uchiha kekkei genkai did?
For a long time that was enough; he was the strongest sentinel his clan had seen since Indra, but his sharingan was strong enough to match it and his chakra was sensitive enough to protect him so the very idea of needing a guide- of being forced to work with someone who would control him- was laughable. And if he had to fend off guides whenever he went into some cities it just demonstrated their greedy, grasping, entitled temperaments and that they wanted control over him but had no mastery over themselves; he wouldn’t quite say that they were lesser but… but he couldn’t make himself respect them (and they way it felt when they tried to pry into his heart, the casual disregard for his mind, the clutching, clinging, sticking invasion of his very self-made it so much harder to bare their presence). There had been less than a dozen guides born into the Uchiha clan ever and even then they hadn’t been very strong; guide ability and the sharingan seemed to be incompatible in a fundamental way but all that meant for Madara was that there was no way he was ever going to take a guide, he didn’t need to and he wouldn’t allow anyone to violate his heart and sense of self like that. Not ever.
Tobirama had hidden his nature from everyone accept his brother and Touka for so long that somedays he liked to lie to himself and pretend that he forgot what he was (it was a weak lie, he could never forget, not with the aching hole in his chest and the sight of his chakra spirt fading away) and that he was nothing more than the Ghost that the world saw; the cold, temperamental, intelligent, (heartless, though that was true) little brother of Hashirama Senju. The Demon that was only rained in by his kind and loving older brother, the one voice that always argued against peace, the great obstacle to alliances with other clans; never mind that he had offered (three times) to leave the Senju and remove the fear of him from the other clans, it would make it easier for Hashirama to make peace he was sure, but Hashirama had never agreed; had instead forbidden him to speak of it again after the last time (Tobirama had been laying in his room recovering from an injury when Hashirama had come in, quiet and tired from advocating for peace- or at least less indiscriminatory death- to the elders who would never listen and to the other clans who refused to believe that he was genuine; Tobirama had known that he was part of the problem and offered- as he had before- to leave the Senju and give up the name, to allow the other clans to make peace without fearing the Demon, it was one of the only times Tobirama had ever seen his brother furious; so angry that he went cold and still when he forbidden Tobirama to speak of it again, forbid him as his brother, as his elder, and as his clan head. They never spoke of it again though the albino knew that both of them thought of it).
And now they had what his brother had always wanted; peace with the Uchiha and the beginnings of the village, which had quickly led to peace with almost all of the clans in Fire County (after all surely Madara could keep the Demon in check and his friendship with Hashirama was famous so the Senju clan leader wouldn’t choose his brother out of hand, not the Ghost over Madara, his oldest and dearest friend) the drop in mortality rates enough to make Hashirama sob; really truly cry the way he never did in public, ugly and aching and hurt. Maybe now Hashirama would take the time to get to know the Uzumaki princess he had almost been betrothed to- the one he still had a picture of hidden in his desk- though he had refused the contract in the end because he couldn’t bring himself to bring children into a world where he would have to bury them before he died; but that was different now, things could be different now. And if there was another guide born to the Senju (unlikely) what happened to Tobirama wouldn’t happen to them in Hashirama’s new world; a world where there were laws to protect and rain in guides and sentinels alike, a world where their father would never have been allowed to spur-break Tobirama, and where guides were not twisted so easily into empty vessels desperate for anything to fill the gaping holes in their souls. (a world where Tobirama’s scars would be from battle and his markings a choice not a necessity, where he would have chosen intimacy instead of being broken to it, where he had hope that his loadstone would even feel anything other than loathing for him)