But the spoiler didn't make it clear if Ulti get defeated or not, it said that Yamato use weird skill and she fall to the ground alongside with the beast pirates, then they escape. Their is nothing about Ulti get defeated, at least what I understand off.
Which is his shit too since he's a part of them and that they are his siblings. And it would be another case of poor writing if he didn't use his devil fruit to allow his siblings to go to Onigashima too.
To remind people saying Luffy would easily trash them out the last weeks, the same character stalling of a YC1+Lvl Character who face soon Kaido. I don't understand the point of downplaying them, nothing is confirmed that they get defeated yet. And the compare with Bm vets doesn't make sense either, I couldn't image Oven and Daifuku could stall a current Luffy, just for the compare. We should be fair and see the stall as good feats for both flyers.