Biako
Alright, so how will Dave and the Undead King come out on top here? I think it might be time for Dog to use the God of War legacy and for Tengu to go full-power mode somehow. You did mention after all that the Gravity Rule had been shaken, which means that the rules of Space have been shaken, so maybe that would allow Lord Tengu to use his sword style to its true power within that area? And that would also be a good opportunity for Blaster to also come in and reach greater height for his Legacy.
Hate to be a buzzkill with a big fight going on, but the math doesn't add up....With 2,5 billion HP, he would've been down to just 2 when the game announced he was at 80%. Adding to that, the rejected attack was said to have shaved off another 10%. All this to say, when Dave checked Ashie's status, his flaming ass should've been at 1,750,000,000.