I think Serene Grace could be able to make Rotom-F at least viable in OU, Discharge and Air Slash coupled with Serene Grace sounds like something that could be very very annoying a set like:
Rotom-F
Trait: Serene grace
Item: Leftovers
EVs: IDK propably a lot HP, some SpA and Spe similar to Rotom-W
-Substitute
-Discharge
-Air Slash
-Pain Split/Volt Switch/HP Ice
wouldn't be bad its main Problem atm is that it barely has anything going for it outside of Air Slash which is a pretty mediocre move, but with Serene Grace it could pull of Paraflinching just using its stabs and with a solid defensive typing that allows it to set-up a substitute rather easy.
I am pretty sure it wouldn't be OU, but it would certainly rise to RU or UU and have some viability in OU as one of the most annoying things ever.
Rotom-F
Trait: Serene grace
Item: Leftovers
EVs: IDK propably a lot HP, some SpA and Spe similar to Rotom-W
-Substitute
-Discharge
-Air Slash
-Pain Split/Volt Switch/HP Ice
wouldn't be bad its main Problem atm is that it barely has anything going for it outside of Air Slash which is a pretty mediocre move, but with Serene Grace it could pull of Paraflinching just using its stabs and with a solid defensive typing that allows it to set-up a substitute rather easy.
I am pretty sure it wouldn't be OU, but it would certainly rise to RU or UU and have some viability in OU as one of the most annoying things ever.