no dude, there is a big difference. First and foremost, Demo offers huge RR to Cold. It’s the only reason Cold Sabo works, believe me. I mean, I know it because I have made the strongest Sabo long ago.. There is also a case of converting a lot of fire into cold thanks to build-enabling belt and cold buffs to FS.
Without Fire RR in Nightblade you can forget about it, unless you wanna stick with farming Main Campaign, then anything will go, frankly.