Fair enough, there are barely hints of Enma turning black soon without a crucial event like ZKK. However, what is exactly about the grim reaper plot tho?
1.In chap 97 ipon matsu is explaining kitetsu and how people die tragic deaths wielding those swords Oda draws a panel with kitetsu in it with a wavy pattern and then he ends ipon matsu words with the sword chooses the swordsman
2. In chap 1033 when zoro removers the old man from his village he remembers being told by him a sword has its own personality a swordsman must master it ,and bend it to his will again in this panel Oda gives us that wavy pattern like he did in chap 97
3. in chap 1038 we are introduced to the reaper who has the wavy background again just like the previous two examples, at this point it’s not a coincidence, and it’s not hallucinating from the medicine that wasn’t even a side affect per the doctors explanation. (chopper I’m 1038, and Miyagi in 1017) idk where it even comes from it’s a lot more likely that this is the personality of the blade more than likely enma we just gotta wait and see how Oda gonna do this.