the dude that comes riding in at the end on the centaur

-Bad Guys launched their invasion.
-The Three Samurai and their allies rallied the kingdom they'd invaded to try and stop them in the field. Partly by pointing out that the Black King will kill them all anyways if not stopped, so they may as well fight and maybe win rather than run and die for sure.
-Bad Guys had their own samurai general, Akechi MItsuhide, to counter the Protagonist Samurai.
-Fight is very messy and violent and dangerous and not going great for the Protagonists, but they hadn't lost yet
-Bad Guys got one of protagonists' allies to turn coat, turning a tight fight worse.
-Toyahisa and his favorite unit of Dwarves went full Battle of Sekigahara and launched a suicide charge to hold off and maul the enemy so the general (Oda) could escape and rally at their castle, just like he did at the start of the manga. This was kind of foreshadowed when the Dwarves first recovered, since they and Toyahisa realized that they both know a similar fighting style (the 'split an enemy's helm and kill him in one single blow' thing)
-Toyahisa took like, all the heads, until the Bad Guys finally sent an End to deal with him and his last survivor Dwarf. He got into a massive brawl with the Shinsengumi Guy, Hijikata Toshizo. Much fight, mutual respect gained.
-Crazy fighter pilot showed up, strafed the hell out of things, crashed, he and his Crack Cat Commandos gunned down more guys (because they had hooked up with Drifter Admiral, and while he has no crew, he DOES have the armory his carrier had for the ship's marines). Then they hijacked a dragon. Because the Sky God is goddamned nuts and works purely on 'SHUT THE HELL UP AND DO WHAT I SAY KICK' logic.
-Toshizo decided to say 'fuck this shit, I'm tired of being used by the Black King, Shinsengumi gonna Shinsengumi our own path now and not be complete dicks like the Black King wants' and strolled off grinning, which is making the Ghost Shinsengumi hanging around him grin too.
-Toyahisa is very sad that his soldiers died while he survived the valiant last stand. Again. Despite his best efforts. He then shows a knack for dragon piloting...and then passes out while doing so because he forgot he was still wounded. Sky God and Cats are unamused.
-Enemy Samurai Strategist Akechi Mitsuhide is panicking because he realizes that A) Nobunaga escaped and B) now he's REALLY angry. Mitsuhide would know that you just don't do 'small' injuries to Oda Nobunaga, it never ends well. Rasputin says sorry, no forces can pursue, everyone's too banged up. Mitsuhide claims that doesn't matter, because taking Nobunaga's head is worth a million soldiers.
-Black King tells him to chill out, reveals Minamato no Yoshitsune had already predicted the battle would end like this and was in pursuit to kill the survivors, which is, from what Yoichi has said, standard tactics for him. This means he's probably going to have a showdown with his old subordinate, Yoichi. Maybe. Yoshitsune is kinda a wild card and does whatever the hell he wants, it's not even super-clear if he's a Drifter or an End.