I mean Kizaru not using his whole strength is kinda obvious at this point, but Luffy is not using his whole strength either. We haven't seen conqueror's coating, we haven't seen Gear 5 (until Luffy grabbed Kizaru).
You can't deny that Kizaru was phased by Luffy's giant grab though.
I hope we get to see Kizaru use his awakened powers and/or conqueror's coating.
If we follow the logic that the guy below used to predict 1092 chapter's title, next chapter will be named "Emperor Luffy" or something of that sort so I don't know what the title could possibly imply.