Wheel of Time

But refresh my memory, do we get any mentions in the books about someone who is not Rand using a flaming sword of Power?

No, but not because it's an unknown or unreasonable weave. It just doesn't happen on-screen. One could argue women are weaker with fire, but fire is still damn useful in life-or-death scenarios and often used anyway.

But I got two takes on this. The first is that it's not really a flaming sword. I've heard at least one or two people guessing that it's a power wrought sword going full anti-myrdraal.

The second? Yeah, it could easily be a weave wreathing a sword in flame (we DO have non-Rand examples of flame-wreathing and other controlled/tied fire weaves, just not directly as weapons)

Let's be honest. Strong return with no lore cost in giving us firesabres once in a while. And it fits the spirit of WoT who, if you recall, DID end up opening a gateway into a volcano for us.