Eiichiro Oda was never a big fan of Death and gave in to eternal rest only to a few characters, mostly during flashbacks. Ace at Marineford followed by Whitebeard are some of those few dead names in the presence of ONE PIECE, and this has repeatedly caused a number of questions and irritations among the public.
With the last chapters of ONE PIECE in Onigashima, however, the irritation grows due to some of the author's decisions, exploded during the release of Chapter 1030. Oda had suggested that some sacrifices would have to be made in order to win the war in Onigashima, but it appears that few people thought of dying and forsaking others. In addition to Ashura Douji, in a state that has not yet been precisely defined after the explosion of the Kanjuro clone, there are mainly three characters who want to return from the dead at all costs.
Kiku, Kin'emon and Kanjuro die and come back to life with tricks and coercion that make many turn up their noses. In Chapter 1030, it was discovered that Kiku is still alive, as is Kanjuro, who once again got the protagonists into trouble using a seemingly unstoppable technique. Kin'emon survived thanks to a near-gag and an explanation that may work but still strongly clashes with context.
It therefore appears that there is one, al maximum two deaths in ONE PIECE during this saga in the protagonist faction. Who knows if in the end it won't be the only Kaido and Big Mom who will die from Wano in the end.