We have some quite interesting tech going on here, like doing some very precise taps for an instant KO, using the "Tensa Zangetsu" without losing control due to hollow/inexperience, or even using awakening asap without taking any damage, or hell using mastered hollowification without any training, I'm suspicious about the fact that this isn't a TAS.
Ichigo would steal the silver arrow from Uryu and jab it through Yhwach's heart himself then stab him through the head with the broken Tensa Zangetsu to set the TYBW world record.
We got to get a sequel to this with thousand year blood war lol! Ichigo speed running to level up and race his way to Yhwach (Juha Baha). Would be so cool to see once the arc is completely animated!
you should have place ichigo lossing the battle with ulquiorra, but when he uses the coins to continue and make the fight more "easier" he unlocks the smash ball (hollowed transformation)
The fact that he's at 0.0 means he hasn't been hit once, which means he's not just going for the WR. He's going to be the first person to do it hitless.