Yeah, no. How high of a resistance to heat does he have? As for the shield, it is not matter, it is literal actual fire, magical fire, that cannot be cut through. It's passive most of the time, unless she willingly drops it.
NLF to say it cannot be cut through when manipulating physics to make a sword cut through anything failed to break it. And again NLF when causality manipulation that could whither anything, didn't do so to it? No, definitely not NLF. The sword is their soul imbued with magic and as such cannot be broken unless you:
1. Power Null
2. Have more magic than the user
Dura neg dudes have tried, hax has tried, so it ain't cutting through.