Lady Kaguya ftw. Fused Momo is scaled up to planet level. Base Momo is off the wall as we didnt really base momo do anything too destructive. besides the tbb at the chunin exam and that 1 was around city level. Amp'd Kaguya off her human juice is Dimension level.
Super Momo was able to shrug off a Rokudo users chidori enhanced katana like nothing. Yet wasn't able to stand against a vanishing baby Rasengan by a baby and was floored by it. His body suddenly became flimsy and pathetic from being impenetrable. Borat goes onto hold a giant Rasengan sustain it and use it. While hding the rasengan he was able to form SCJ without his hands and divide his concentration from the Rasengan, catch Momo with a Boruto stream and hurt him (something even kakashi could avoid) then dodge his super human speed attacks and hit him with a vanishing rasengan again and hurt him (Rokuo chidori katana couldn't dent him). Thwn go onto finish SuperMomo and his super charged attacks with a rasengan boosted by a base Naruto who had to go Chakra mode to even fight and hurt Super momo. Yeah and momo gives a seal from his rear end.
Although Sasuke and Naruto vs Momo was manyfold better and Momo wasn't a retard till the end.
If fused Momoshiki can absorb Kaguya easily, then i will go with him. Otherwise, Kaguya is immortal and can only be defeated by being sealed, so she takes this.
Momo had he not (rather unfortunately) been waned to have lesser reactional skill than a power stripped Kakashi. Kaguya also had the hard to deal with seal that made it impossible generically defeating her.