If it's raining Then there's probably thunder if Juvia does thia right she can get Suigetsu stuck with lightning being he walks around with that giant sword which would act as a lightning rod. That would nullify Suigetsu's liquidations.
This is pretty much a stalemate. I mean...Yeah. I don't see either one of them winning this. Suigetsu would probably get bored before Juvia. But if Gray walks by, then Suigetsu wins because Juvia will wander off like a dolt.