By the way, if anyone was curious about any more organized close combat choreography from Stampede's ep12 finale, my short answer would be.....uhhhhh lmao, not really? :'D

Except for a few familiar tonfa-gun parries while Vash deliberately shielded Meryl for her to escape (note how he takes his eyes off Knives for a moment to check back on her, likely his nonverbal signal she acknowledges from him to go), the close gunshot that Knives deliberately matrix-dodged away, and the cool midair backflip Vash did outside, the entire final boss 'fight' was pretty much the most elaborate 'disorganized' game of keep away + hot potato (with unleashed knife-throwing & gunslinging around a literal MacGuffin nuke) between two non-human siblings just going completely ham feral: biting, thrashing, slamming, bodily throwing, and kicking each other inelegantly all over the place. (Spiced with tons of 'rule of cool,' staged inside, outside, midair, and in space!)

It's notable because except for that one dodged shot it seemed like Vash aimed at Knives' neck(?) almost all of his shooting was purposely (characteristically) done to disarm and temporarily stun/stagger/disable at places like arms, shoulders, and legs etc to get Knives to slow down and back off. (That, and Knives was basically impervious to bullet wounds anyway, even the 'upgraded' shells with Plant markings.)

This is important because despite how fancy, powerful, and batshit dangerous it seemed, they were not fighting to kill each other. :O Yes, even Knives! Because if he really wanted to (aka if he was pure evil and didn't care about Vash, thankfully untrue), he could have chopped off Vash's other arm & legs (or worse) to get the thing he wanted, but no - that's not how he handled or approached the fight either, despite how pissed off and desperate he was. Most of the time (that I could see) he was thrashing his literal knives (long distance) around to shake him off (ex: grabbing his leg and tossing him) to get Vash to drop/lose his grip on the cube, and up close he was grabbing/flailing with his bare hands (no bared weapons--he kept those off, or even with any...actual technique?? lol Knives is not a trained 'human' fighter) trying to reach the thing while shouting/arguing in Vash's face. (Vash is the one who bit him in response, literally having both his hands full.)

Noteworthy because even after studying gifs of the whole fight and rewatching the ep, not once did I ever catch a lethally aimed attack (with express intent to hurt or maim with malice) from Knives at Vash! :O (Knives' priority was aiming for the cube, not so much at Vash.) Unlike how he instantly slaughtered all the spectating soldiers in half who interfered (and hurt Vash.)

So that's right, the only damage Vash sustained was from the human soldiers who shot at him - at least twice across his chest and once thru his foot (see gifs, the rest his jacket looked bullet-proof, ricocheting off him), and the only damage Knives received was when he purposely threw himself into the final Angel Arm blast, against Vash's desperate pleading at him to stop. :'D Ohhh these poor tragic dysfunctional siblings who still very much care for each other...