My first thought about yonkou is each yonkou have different type of fighting like WB with paramecia BM With logia Kaido with zoan and Shanks with haki (not df ) and im wrong (i still dont believe im wrong) . Because i think kaido have zoan devil fruit which i think he have satan form or evil form something like that ( and when kaido appears falling from sky island, i guess my thought was wrong). And then i thought big mom have liquid devil fruit (which now she have soul devil fruit). And now im still believe that kaido have zoan devil fruit more like satan or evil form. Is big mom devil fruit logia? I think she can turn her body into soul you know all body not like brook (his soul out of body but big mom turn body into soul). What dou you guys think about their devil fruit? If you have in mind let me know.