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I would be surprised if after all that buildup the Second User's Quirk does nothing. Feels like it's going to be the one that's the big game changer in turning the tide of battle. Also depends on if we do get another OFA info dump right before the big conclusion, so they can fill in some of the missing pieces regarding who the 2nd and 3rd users actually are and what happened with them and OFA.
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He not only has his multi-sword again, but don't you think Spinner looks buffer than usual? If it turns out AFO jacked him up with several additional Quirks and now he's turned into a hulking beast, that's going to be really cool and a fun twist to everything, especially after none of the Heroes thinking of him as a threat prior.