Kizaru and GB being a pair of super mooks who simply serve as a Sanji/Zoro boss fights and nothing else.
Kizaru especially is so intriguing. I genuinely hope he joins Akainu/Kuzan in terms of plot relevance, because it really feels that Oda has been holding back his true power and personality in a way that might prove momentous later.
As for GB, the contrast between his initial personality and his behaviour in Wano interests me. There is potential there for him and Fuji to be secretly engaging in some double-agent Good Cop-Bad Cop shenaniganry, methinks.